Antoine Guillemin Adolphe Brongniart.

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round the central part of the stomach, the posterior end curved
round the hermaphrodite gland ; the smaller lobe applied to
the hinder part of the intestine^ sending a process into each
bend, the posterior extremity Ijing along the rectum. The
lobulation of the liver is conspicuous upon its lower surface ;
the colour uniform, bright and essentially composed of
yellow and pink. The liver adheres strongly to the base of
the stomach, and to the first part of the intestine.

Reproductive System. — Hermaphrodite gland y^rj large,
pyriform, of from five to six lobes, each of which consists of
trom ten to fifteen lobules ; colour milky. The gland lies in
the concavity formed by the curved posterior extremity of the
larger lobe of the liver, and is partlv enclosed by the small lobe.
It adheres slightly to the liver, but is entirely free in some
individuals. Duct of hermaphrodite gland laree, twice as long
as the gland, more or less sinuous, of uniform diameter.
AUmminiparous gland unequally bilobed, convex posteriorly,
excavated in front and receiving the duct of the hermaphrodite
gland, subdivided into irregular lobules, position transverse.
Oviduct — ^prostatic portion wide, sinuous, white, translucent,
the dilated part remote from the albuminiparous gland, origin
from gland not terminal ; infraprostatic portion much curved^
constituting nearly half the oviduct. Spermatheca spherical,



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254 M. F. d'A. Furtado on Viquesnelia atlantica.

attached to the anterior end of the uterus, its canal attached
(externally) to the oviduct. Vestibule as long as the oviduct
(neglecting the convolutions of the latter), variously curved
or reduplicate. Penis short, depressed, situate in the middle
of the vestibule, bifid, of a delicate yellow-pink colour ; vas
deferens entering the anterior lobe*.

Shell. — I have nothing to add to M. Morelet's description,
which is as follows : — " T. ancyliformis, oblonga, planata,
rugosiuscula, longitudinaliter costulata, fulvescens ; spira
brevis, lateralis, postica, apice albido."

Note. — I have not found Viquesnelia atlantica in the

fardens of Ponta Delgarda, where it was discovered by MM.
[orelet and Drouet. The specimens upon which this memoir
is founded were caught on Oct. 31, 1880, on the mountains
near 7 Cidades, near the aqueducts of Muro do Carvao and
Muro das 9 Janellas, on stones and overturned masses of
Sphagnum. Specimens collected in the same neighbourhood
in the month of May had the albuminiparous gland so slightly
developed that it was necessary, in order to complete the
study of the reproductive organs, to wait for the breeding-
season ; in May the spermatheca was so small as to escape
observation.

EXPLANATION OF PLATE XIH.

Viquesnelia atlantica,

Fips, \f 2. Animal (nat. size).

jy. 3. Occasional attitude when beginning to creep.

Fig. 4. Tail-end (magnified).

* [It will be seen from M. Furtado's description that ViqueaneUa is
similar in anatomical structure to Limax and the allied ffenera. The
mandible connects it with Viirinaj Syalina, and Limax; and it would go
with those genera into Morch's "Oxygnatha'* (** maxilla laevis, acie
gimplici "). It can hardly be doubted, however, that too much stress
has been laid upon characters taken from the mandible. This is inci-
dentally shown oy M. Furtado in a paper entitled " Indaga^des sobre
a compliciucjlo das Maxillas da alguns Helices naturaHsados nos A9ores ''
(Lisbon, 1880), in which he shows that in Azorean examples of HeUx
piaana, lactea, and aspersa the mandible is singularly variable and often
differs conspicuously from Moquin-Tandon^s description of the sameonran
in European specimens of what are believed to be the same species. The
lingual nbbon seems to connect Viquesnelia with Testacella, to which it is
otherwise only remotely allied. It is hardly possible at present to discuss
the exact place of Vitrina and ViquesneUa in the lon^ chain of genera and
subgenera which intervenes between Limax and Hebx, though they seem
to approach the first genus rather than the second. Muc% anatomical
research is required to define these forms and discover their mutual rela-
tions ; and M. Furtado^s paper is a welcome addition to the materials
already collected. — ^M.]



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Mr. S. H. Scudder on Devonian Insects. 265

Fig, 5. Median part of radula (magnified).

Fig, 6. Lateral part of radula.

Ftp. 7. Marina! part of radula.

jFy. 8. Mandible (magnified).

Fig, 9. Reproductive organs, hg^ hermanhrodite ^land ; e, its efferent
duct; Mj albuminiferous gland; orf, oviduct (prostatic por-
tion); od', oviduct (infraprostatic portion) ; 9p, spermatheca;
vd, vas deferens ; pey penis ; v, vestibule.

Figs, 10, 11. Shell (magnified).



XXIII. — Relation of Devonian Insects to Laier and Existing
Types. By Samuel H. Scudder*.

It only remains to sum up the results of this reexamination
of the Devonian insects, and especially to discuss their rela-
tion to later or now existing types. This may best be done
by a separate consideration of the following points : —

1. There is nothing in the structure of these earliest-known
insects to interfere with a former conclusion t that the general
type of wing-structure has remained unaltered from the earliest
times. Three of these six insects [Gerephemera^ HomothetuSy
and Xenoneura) have been shown to possess a very peculiar
neuration. dissimilar to both Carboniferous and modern
types. As will also be shown under the tenth head, the dis-
similarity of structure of all the Devonian insects is much
greater than would be anticipated; yet all the features of
neuration can be brought into perfect harmony with the
system laid down by Heer.

2. These earliest insects were Hexapodsy and, as far as the
record goes, preceded in time both Arachnids and Myriopods.
This is shown only by the wings, which in all known insects
belong only to Hexapods, and in the nature of things prove
the earlier apparition of that group. This, however, is so
improbable on any hypothesis, that we must conclude the
record to be defective.

3. They were ail lower JBeterometcAola. As wings are the
only parts preserved, we cannot tell from the remains them-
selves whether they belong to sucking or to biting insects ;
for, as was shown in the essay already referred to, this point
must be considered undetermined concerning many of the
older insects until more complete remains are discovered.

• Prom the ' American Journal of Science/ Feb. 1881.

This summaiy of results is the conclusion of a memoir b^ Mr. Scud-
der " On the Devonian Insects of New Brunswick,** published in the
* Anniversarv Memoirs of the Boston Society of Natural History/ 1880.

t " The Eariy Types of Insects/* Mem. Bost, Soc Nat. Hist. iii. p. 21.



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256 Mr. S. H. Scudder on the Relation of

Thejr are all allied or belong to the Neoroptera, usiiig the
word in its widest sense. At least two of the genera {Plate-
phemera and Gerephemera) must be considered as having a
closer relationship to Fseudoneuroptera than to Neoroptera
proper, and as having indeed no special affinity to the true
Weuroptera other than is found in Palseodictyoptera. Two
others {Lithentomum and Xenoneura)^ on the contrary, are
plainly more nearly related to the true Neuroptera than to the
i^seudoneuroptera^ and also show no special affinity to true
Neuroptera other than is found in Palaeodictyoptera. A fifth
{Hofnothetu8)y which has comparatively little in common with
the Palaeodictyoptera, is pernaps more nearly related to the
true Neuroptera than to the Fseudoneuroptera, although its
pseudoneuropterous characters are of a striking nature. Of
the sixth {Dyscritus) the remains are far too imperfect to judge
clearly ; but the choice lies rather with the Pseudoneuroptera
or with Homoihetus. The Devonian insects are then about
equally divided in structural features between Neuroptera
proper and Pseudoneuroptera ; and none exhibit any special
orthopterous, hemipterous, or coleopterous characteristics.

4. Nearly all are synthetic types of a comparatively narrow .
range. This has been stated m substance in the preceding
paragraph, but may receive additional illustration here. Thus
JPlatephemera may be looked upon as an Ephemerid with an
odonate reticulation ; Homothetus mi^ht be designated as a
Sialid with an odoiiate structure of the main branch of the
scapular vein ; and under each of the species will be found
detailed accounts of any combination of the characters which
it possesses.

6. Nearly all bear marks of affinity to the Carboniferous
Paloeodictyopteraj either in the reticulated surface of the wing,
its longitudmal neuration, or both. But besides this there are
some, such as Gerephemera and Xenoneuraj in which the
resemblance is marked. Most of the species, however, even
including the two mentioned, show palseodictyopterous charac-
ters only on what might be called the neuropterous side ; and
their divergence from the Carboniferous Palaeodictyoptera is
so CTcat that they can scarcely beplaced directly with the mass
of Palaeozoic insects, where we mid a very common type of
wing-structure^ into which the neuration of Devonian insects
only partially fits. For

6. On the other handy they are often of more and not less
complicated structure than most Palaeodictyoptera. This is
true of the three genera mentioned above with peculiar neu-
ration, but not necessarily of the others ; and it is especially
true when they are compared with the genus Dictyoneura and



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Devonian Insects to Later and Existing Types. 257

its immediate allies. There are other Pateodictyoptera in the
Carboniferous period with more complicated neuration than
Dictyoneura ; but these three Devonian insects apparently
surpass them, as well as very nearly all other Carboniferous
insects. Furthermore,

7. With the exception of the general statement under the
fifth head, they hear little special relation to Garhoniferous
forms^ having a distinct fades of their own. This is very
striking ; it would certainly not be possible to collect six wings
in one locality in the Carboniferous rocks which would not
prove, by their affinitv with those already known, the Carbo-
niferous age of the deposit. Yet we find in this Devonian
locality not a single one of PalseoblattarisB, or any thing
resembling them ; and more than half the known insects of
the Carboniferous period belong to that type. The next most
prevailing Carboniferous type is Dictyoneura and its near
allies, with their reticulated wings. Oerephemera only of all
the Devonian insects shows any real and close affinity with
them; and even here the details of the wing-structure, as
shown above, are very different. The apical half of the wing
of Xenoneura (as I have supposed it to be formed) also bears
a striking resemblance to the Dictyoneuran wing; but the
base (which is preserved, and where the more important
features lie) is totally different. The only other wing which
shows particular resemblance to any Carboniferous form (we
must omit Dyscritus from this consideration, as being too im-
perfect to be of any value) is Plat^hemeray where we find a
certain general resemblance to JEphemerites RUckertij Gein.,
and Acndites priscus^ Andr. ; but this is simply in the form of
the wing and the general course of the nervules ; when we
examine the details of the neuration more closely, we find it
altogether different, and the reticulation of the wing polygo-
nal, and not quadrate as in the Carboniferous tvpes *. In
this respect, indeed, Platephemera differs not only from all
modem Ephemeridse, but also from those of other geolorical
periods t- Another prevailing Carboniferous type, the Ter-
mitina, is altogether absent from the Devonian. Half a dozen
wings, therefore, from rocks known to be either Devonian or
Carboniferous would probably establish their age.

* Dr. H. B. G^dnitz has kindly reexamined JBpkemeritea Ruckarti at
my lequeet; and states that the redcuhition is in general tetragonal, but
that at the extreme outer margin the cells appear in a few places to be
elliptical five- or six-sided.

t The Dictyoneura and their allies, as may be inferred, are considered
as belonging to the Pakeodictyoptera, although their ephemeridan affini-
ties are not disregarded.

Ann. & Mag. N. Hist. Scr. 5. Vol. vii. 19



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258 Mr. S, H. Scudder on the Relation of

8. 77ie Devonian insect^ were ofgreai size^ had membranous
toings, and were probably aquatic in early life. The last state-
ment is simply inferred from the fact that all the modern types
most nearly allied to them are now aquatic. As to the first,
some statements have already been made; their expanse of
wing probably varied from 40 to 175 miliims., and averaged
107 miliims. Xenoneura was much smaller than any of the
others, its expanse not exceeding 4 centims., while the pro-
bable expanse of all the rest was generally more than a deci-
metre, only HomothettLS falling below this figure. Indeed, if
Xenoneura be omitted, the average expanse of wing was
121 miliims., an expanse which might well be compared to
that of the uEschnidae, the largest, as a group, of living
Odonata. There is no trace of coriaceous structure in any of
the wings ; nor in any are there thickened and approximate
nervules— one stage of the approach to a coriaceous texture.

9. Some of the Devonian insects are plainly precursors of
existing forms^ while others seem to have left no trace. The
best examples of the former are Flatepfiemeraj an aberrant
form of an existing family, and Eomothetus, which, while
totally different in the combination of its characters from any
thing known among living or fossil insects, is the only Palaeo-
zoic insect possessing that peculiar arrangement of vems found
at the base of the wings of the Odonata, typified by the arcu-
lus, a structure previously known only as early as the Jurassic.
Examples of the latter are Gerephemera^ which has a multi-
plicity of simple parallel veins next the costal marrin of the
wing, such as no other insect, ancient or modem, is known to
possess, and Xenoneura . where the relationship of the intemo-
median branches to each other and to the rest of the wing is
altogether abnormal. If, too, the concentric ridges, formerly
interpreted by me as possibly representing a stridulating organ,
should eventually be proved an actual part of the wing, we
should have here a structure which has never since been
repeated even in any modified form.

10. They show a remarkable variety of structure^ indicating
an abundance of insect life at that epoch. This is the more
noticeable from their belonging to a single type of forms, as
stated under the seventh head, where we have seen that their
neuration does not accord with the commoner type of wing-
structure found in Palaeozoic insects*. These six wings
exhibit a diversity of neuration quite as great as is found
among the hundred or more species of the Carboniferous
epoch : in some, such as Platephemeray the structure is very
simple ; in others, like Homoihetus and Xenoneura^ it is some*^

• Cf. Mem. Boat Soc. Nat. Hiflt. iii. 19, note 1.



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Devonian Insects to Later and Existing Types. 269

what complicated : some of the wings, as Platephemera and
Gerephemeray are reticulated ; the others possess only trans-
verse cross veins, more or less distinct and direct. No two
wings can be referred to the same family, unless Dyscritus
belongs with Homothetus — a point which cannot be determined,
from the great imperfection of the former. This compels us
to admit the strong probability of an abundant insect-fauna
at that epoch. Although many Palaeozoic localities can boast
a greater diversity of insect types if we look upon their general
structure as developed in after ages, not one in the world has
produced wings exhibiting in themselves a wider diversity of
neuration ; for the neuration of the Palaeodictyoptera is not
more essentially distinct from that of the Palaaoblattariae or of
the ancient Termitina than that of Platephemera or Gerephe-
mera on the one hand is from that of Homothetus or Xenoneura
on the other. Unconsciously, perhaps, we allow our knowledge
of existing types and their past history to modify our appre-
ciation of distmctions between ancient forms. For while we
can plainly see in the Palseoblattarise the progenitors of living
insects of one order, and in other ancient types the ancestors
of living representatives of another order, were we unfamiliar
with the divergence of these orders in modem times, we
should not think of separating ordinarily their ancestors of
the Carboniferous epoch. It may easily be seen, then, how
it is possible to find in these Devonian insects (all Neuroptera
or neuropterous Palaeodictyoptera) a diversity of wing-struc-
ture greater than is found in the Carboniferous representatives
of the modern Neuroptera, Orthoptera, and Hemiptera.

11. The Devonian insects also differ remarkMy from all
other known types j ancient or modern ; and some of them
appear to he even more complicated than their nearest living
aUies. With the exception of Flatephemeray not one of them
can be referred to any familv of insects previously known,
living or fossil; and even Platqphemeraj as shown above,
differs strikingly from all other members of the family in
which it is placed, both in general neuration and in reticula-
tion, to a greater degree even than the most aberrant genera
of that family do from the normal type. This same genus is
also more complicated in wing-structure than its modem
allies ; the reticulation of the wing in certain stracturally-
defined areas is polygonal and tolerably regular, instead of
being simply quadrate, while the intercalated veins are all
connected at their base, instead of being free. Xenoneura
also, as compared with modem Sialina, shows what should
perhaps be deemed a higher (or at least a later) type of struc-
ture, m the amalgamation of the extemo-median and scapular

19*



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260 Mr. S. H. Scudder on Devonian Insects.

veins for a long distance from the base, and in the peculiar
structure and lateral attachments of the intemo-median veins ;
in the minuter and feebler cross venation, however, it has an
opposite character.

12. We appear y there/brej to be no nearer the heginnxng of
things in the Devonian gpoch than in the Carboniferous y so far
as either greater unity or simplicity of structure is concerned ;
and these earlier forms cannot be used to any better advan-
tage than the Cai-boniferous tjpes in support of anv special
theory of the origin of insects. All such theories have re-
quired some Zoeay Leptus, Campodeay or other simple wing-
less form as the foundation-point ; and this ancestral form,
according to Hackel at least, must be looked for above the
Silurian rocks. Yet we have in the Devonian no traces
whatever of such forms, but^ on the contrary, as far down as
the middle of this period, wmged insects with rather highly
differentiated structure, which, taken together, can be consi-
dered lower than the mass of the Upper Carboniferous insects
only bj the absence of the very few Hemiptera and Coleo-
ptera which the latter can boast. Remove those few insects
from consideration (or simply leave out of mind their future
development to very distinct types), and the Middle Devonian
insects would not suffer in the comparison with those of the
Upper Carboniferous, either in complication or in diversity of
structure. Furthermore, they show no sort of approach
toward either of the lower wingless forms hypothetically
looked upon as the ancestors of tracheate Articulata.

13. Finally y while there are some forms which to some degree
bear out expectations based on the general derivative hypothesis
of structural devehpmenty there are quite as many which are
altogether unexpectedy and cannot be explained by that theory
toithout involving suppositions fyr which no facts can at present
be adduced, P(dy)hemera and Gerephemera are unquestionably
insects of a very low organization related to the existing may-
flies, which are well known to be of inferior structure as com-
pared with other living insects ; these may-flies are indeed
among the most degraded of the suborder to which they
belong, itself one of the very lowest suborders. Dyscritus too
may be of similar degradation, although its resemblance to
Homothetus leaves it altogether uncertain. But no one of
these exhibits any inferiority of structure when compared
with its nearest allies in the later Carboniferous rocks ; and
they are all higher than some which might be named ; while
of the remaining species it can be confidently asserted that
they are higher in structure than most of the Carboniferous
types, and exhibit syntheses of character differing from theirs.



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Dr. Wallich on Siliceoits Sponge-ffrowth. 261

It is quite as if we were on two distinct lines of descent when
we study the Devonian and the Carboniferous insects : they
have little in common ; and each its peculiar comprehensive
types. Judging from this point of view, it would be impos-
sible to say that the Devonian insects showed either a broader
synthesis or a ruder type than the Carboniferous. This, of
course, may be, and in all probability is, because our know-
ledge of the Carboniferous insects is in comparison so much
more extensive ; but, judging simply by the facts at hand,
it appears that the Carboniferous insects carry us back both
to the more simple and to the more generalized forms. We
have nothing in the Devonian so simple as EuepkemeriteSj
nothing so comprehensive as Eugereony nothing at once so
simple and comprehensive as Dictyoneura, On the derivative
hypothesis we must presume, from our present knowledge of
Devonian insects : — that the Palseodictyoptera of the Carboni-
ferous are already, in that epoch, an old and persistent em-
bryonic type (as the living Ephemeridae may be considered
today, on a narrower but more lengthened scale) ; that some
other insects of Carboniferous times, together with most of
those of the Devonian, descended from a common stock in the
Lower Devonian or Silurian period ; and that the union of
these with the Palaeodictyoptera was even further removed
from us in time, carrying back the origin of winged insects
to a far remoter antiquitv than has ever been ascribed to them,
and necessitating a taith in the derivative hypothesis which
a study of the records preserved in the rocks could never alone
aflTord ; for no evidence can be adduced in its favour based
only on such investigations. The profound voids in our
knowledge of the earliest history of insects, to which allusion
was made at the close of my paper " On the Early Types of
Insects," are thus shown to be even greater and more obscure
than had been presumed. But I should hesitate to close this
summary without expressing the conviction that some such
earlier imknown comprehensive types as are indicated above
did exist and should be sought.



XXIV. — On Siliceous Sponge-growth in the Cretaceoua Ocean.
By Surgeon-Major Wallich, M.D.

A FEW days after the publication of the 'Annals' for
February, I obtained a sight of Mr. G- J. Hinde's verj in-
teresting little work On Fossil Sponge-spicules found m the



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262 Dr. Wallich on Siliceous Sponge-growth.

Interior of a single FHntstone from Horstead in Norfolk,
which had just previously been published at Munich.

In his concluding remarks the author, while refemng to
my paper on the chalk flints (Quart. Journ. GeoL Soc, Feb.
1880), expresses the opinion that " the contents of the flint
from Horstead, and of tnose from the North of Ireland, prove "
what I only " assumed, namely that in its original condition
the cretaceous ooze was, like that of the Atlantic deep-sea
mud, filled with the spicular skeletons of sponges .... the
contents of both the Irish and Horstead flints showing that
the sponge-spicules are as much intermingled with Foramini-
fera and other calcareous organisms as in the Atlantic ooze,
and that therefore both these animal types flourished con-
temporaneously " (op. ciu pp. 80, 81).

Without in any wise detracting from the value of the con-
current testimony thus furnished as to the great exuberance
and variety of the sponge-life which existed at the bottom of
the ancient cretaceous sea-bed, the Horstead nodule, per se^
would increase rather than diminish the force of the objec-
tions that have been raised by some writers to any analogy



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