Alexander Winchell.

Enumeration of fossils collected in Niagara limestone at Chicago, Illinois ; With descriptions of several new species online

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__ Enumeration of Fossils collected in the Niagara Limestone at Chicago, Illinois ; ivith Descriptions
of several New Species. By Prof. ALEXANDER WINCHELL and Prof. OLIVER MARC Y.


ly* Read January 4th, 1865.

JMORE than a year ago, some fossils came into our hands from the quarries in the south
part of the city of Chicago, Illinois, in a suburb known as Bridgeport, which seemed to pos-
sess an unusual degree of interest. We at once visited the place, and subsequently adopted
p measures to procure as complete a collection as possible of the fossils of the locality. Be-
lieving that an exhibition of the ancient fauna which once lived upon the spot would pos-
sess considerable geological interest, we have made note of every species which has fallen
under our observation, and, by an understanding with Mr. Worthen, the State geologist of
Illinois, offer the results of our studies in the following paper:

The rock at the principal quarry is a limestone, which, to a considerable extent, is in a
broken and amorphous condition. The entire mass, in consequence of the partial or com-
plete destruction of the fossils, has assumed an extremely vesicular structure. The upper
portion seems to be somewhat magnesian; it is of a pale buff color, more massive than the
lower, and contains nearly all the species enumerated in the present paper. Its thickness at
the quarry is about eighteen feet. The lower portion is of a bluish color, generally harder
in its solid parts, but somewhat diversified with patches of an argillaceous character. It
has not been quarried to any considerable extent, and the excavations do not penetrate it a
greater distance than about four feet. It is only in this part that we find those interesting
species, Acidaspis Ida, Ischadites tessellatus, and Gomphoceras Marcyce. The whole mass of the
rock, both above and below, is a congeries of organic remains, three fourths of which are
reduced to an unrecognizable condition, and many of which have been totally or partially
dissolved out, showing, in some instances, the delicate tracery of the exterior, or compli-
cated internal structure, in an extraordinary state of preservation.

We do not intend to be understood by what is stated above, of the upper and lower
portions of the exposure, that in our opinion we recognize here the line of demarcation
between two stages of the formation, not considering our data sufficient to justify a con-
clusion on this point.

According to Mr. Worthen, the rocks at this locality are lithologically and paleontologi-
cally identifiable with the Leclaire limestone at the upper rapids of the Mississippi, near
Leclaire, Iowa, and Port Byron, Illinois. 1 Mr. Worthen states that a Bryozoan form resem-
bling Didyonema retiformis, Myalina mytiliformis, Strophomena depressa, a small Pentamerus re-
sembling P. galeatus, and three or four species of chambered shells belonging to the genera
Orthoceras and Cyrtoceras, are common to the Leclaire and Chicago limestones, establishing
an identity between the two, as he thinks ; while the Niagara age of the latter is shown by
the number of Niagara species which it contains.

Professor Hall (Iowa Geol. Rep., p. 73,) had previously supposed the Leclaire limestone
might be the western equivalent of the Gait limestone of Canada West, though he subse-
quently recognized the evidences of its belonging to the age of the Niagara group, occu-
pying a position probably in the upper part of the group. 2

1 Amer. Jour. Sc. and Arts. vol. xxxiii. p. 46, 1862. a Wiscon. Geol. Rep., pp. 67 et seq. and 446 el seq.



Our own investigations in the Chicago limestone which are the first to bring into
prominent notice this interesting locality seem to confirm, beyond all controversy, Mr.
Worthen's opinion of the age of the rock, as the following table will show ; and by estab-
lishing, through numerous identifications, given below, its parallelism with the Racine lime-
stone, admitted to be equivalent to the Leclaire limestone, it becomes geologically
demonstrated that all these limestones occupy a position in the Niagara group of New

But with which member of the group shall they be synchronized ? Our own identifications
tend to show a relationship with both the Niagara limestone and the Niagara shale ; of those
species, however, which, at the East, occur in the Niagara shale, it will be observed that
some, as Slrophomena rhomboidalis, Atrypa relicularis, Spirifera crispa, JS. radiata, Meristella nitida,
and Rhynchonella mglecta, are species which enjoyed either a great geological or great geo-
graphical range, or both together, and are thus proved to have been wanting in that sen-
sibility to geological variations which is requisite in fossils relied upon for stratigraphical
determinations. The same may perhaps be said of Caryocrinus ornatus and Lozonema subulata.
Of the others, the Poli/zoa may be regarded as only provisionally identified. There is left,
then, no strong bond of alliance between the Chicago limestone and the Niagara shale, ex-
cept the prevalence of crinoidal remains in both. But it will be noticed that we have been
unable to identify any species except Caryocrinus ornatus ; so that, admitting the alliance
shadowed forth by the presence of the crinoidal type in considerable force, we have a
much stronger affinity established with the Niagara limestone by the identification of sev-
eral species of true corals, as well as by the abundance of individuals of this type. For the
present, therefore, it seems to us that the Chicago, Racine, and Leclaire limestones exhibit a
satisfactory affinity with the Niagara limestone of New York.

We have detected in the Chicago limestone no less than eighty-two species, of which
thirty-nine seem to be hitherto undescribed. If we add to these the few additional species
described by McChesney, from the same locality, we find that a single quarry has furnished
not less than eighty-seven species, another evidence of the abundance and variety of life
which teemed in the paleozoic seas.

None of the Gasteropoda or Cephalopoda have been identified with New York species.
Of the identifications with New York species, the corals are all (except Pctraia calicula)
from the Niagara limestone, and the mollusks (including Bryozoa) are all from the Niagara

It is noticeable that we do not find in our collection any specimens of HeliolUes, Eucalyp-
tocrimis decorus, Orthis elegantula, Spirifera nm/arensis, Pentamcrus oblongm, Rhynchonella cmieata,
or Calymene.

Of the old species recognized by us, all have been described from the Niagara group of
North America. Loxonema subulata Conrad, was, however, originally described from the
Clinton group of New York, but has been identified in the Niagara group of Canada West,
as well as at Chicago. The geographical distribution of these species in some of the North-
western States, Canada West, and Europe, is presented at a glance in the following table :




N. Y.








Dipliyphyllum ctespitosum Hall sp

Favosites gothlandica Lam


" reticulata Hall


















" nodostriata Hall

Meristella nitida Hall sp

Rliynchonella neMecta Hall








* Pterinea ne^lecta McChesney sp

Ambonychia mytiloidea Hall

Pleurotomaria Halei Hall

" Hoyi Hall

Loxonema subulata Con

* Orthoceras Laphami McChenesy

Cyrtoceras Foster! Hall


Petraia calicula Hall sp., Pal. N. Y., ii. p. Ill, pi. xxxii. fig. 1, a-Jc.

Zaphrentis turbinatus Hall sp., Pal. N. Y., ii. p. 112, pi. xxxii. fig. 2.

Cysiipliyllum sp ? A fragment generically well marked.

Diphyphyllum ccespitosiim Hall sp., Pal. N. Y., ii. p. 116, pi. xxxiii. fig. 1, a-b.

Favosites gothlandica Lam. (F. niagarensis Hall.) We adopt the suggestion of Billings
(Canad. Journal, March, 1859, p. 99), in referring this form back to the original species. It
occurs abundantly in the upper part of the quarry.

Favosites venustus ? Hall sp., Pal. N. Y., ii. p. 120, pi. xxxiv. fig. 1, a - i.

The agreement is not striking. This is an expanded, incrusting coral, adapting itself to
the inequalities of the underlying surface, and, in places, developing tubercular masses.
The tubes are ordinarily not more than an eighth of an inch long, but, in the tubercles
become sometimes half an inch in length. In the tuberculous parts, the diaphragms are
seen to be direct and crowded. No indications of a radial system are seen. The cell-
mouths are conformable to this species. The Chicago fossil bears considerable resemblance
to Thecostcgites hemisphcericus Rom. (Sil. Fauna des Westl. Tenn. Taf. ii. fig. 3).

* These species are not enumerated by Hall among the fossils of Wisconsin.



Cladopora lichenoides W. and M.
Plate II. figure 1.

Polypary consisting of a mass of crowded cylindrical tubes arranged in ramose and folia-
ceous forms, both forms being sometimes united in one specimen. The earlier growth, in
one of our specimens, is explanate. The cells are elongated, obliquely horizontal, crowded,
overlapping, with their mouths opening obliquely through the epitheca. The frond devel-
ops into an irregularly undulate form, sometimes dividing, and some of the lobes bending
round laterally, after the manner of one or two turns of an Archimedes. From the border of
the frond arise terete, bifurcating branches, with the mouths opening on all sides. All the
cell-mouths are somewhat crescentiform, the outer lip often slightly indented, and some-
times sufficiently so to give the mouth a triangular outline.

In exfoliated, weathered specimens, the cells are seen to be cylindrical and separately
walled, but closely in contact. The width of three of these cells occupies the space of one
tenth of an inch ; their length is about a third of an inch. No evidences of septa or la-
mellse can be detected.

The cell-mouths of this abundant and beautiful species resemble Ccenites, Alveolttes, and
Cladopora. The fossil differs from Ccenites and Cladopora in not having a solid coenenchyma,
and at least from the usual forms in its foliaceous ememble. It differs from Alveolites in
the want of intra-cellular structure. Some species of Cladopora figured by Hall, however,
exhibit generic characters to which the present species is sufficiently conformable.

Cladopora verticillata W. and M.
Plate II. figure 2.

Corallum arising in the form of a stem, from which spreads out, horizontally, in all direc-
tions, a thin and delicate frond, composed of small radiating cells continually multiplying
in number with the distance from the axis. This circular frond is covered superiorly by
an epitheca through which the cell-mouths open as in other species. The mouths are tri-
angular-crescentic ; the cells show traces of dissepiments. At the height of an inch and a
half above the first frond is another, in all respects similar, and a cylindrical perforation
runs through the rock from one to the other. This structure has been seen in two unmis-
takable specimens. It seems probable that other verticils or circular fronds occur between
the two observed, and that the whole space was originally filled up with verticils of cells
alternating with plates of epitheca ; but of this we have no other evidence than the porous
condition of the rock, with occasional traces of minute coral tubes.

In the specimen which is the subject of this description, a second stem, smaller than the
first, is seen perforating the rock for the depth of half an inch, and sending out a verticil
which becomes confluent with that of the larger specimen. Is this a new colony rooted,
banyan-like, from the branches of a parent ?

The axis in our specimens is hollow. The filling is a calcareous clay, showing no other
structure than a slight porousness, with obscure vertical striations on the exterior. We


might be permitted to infer, from analogy, that the original axis was solid, and resembled
the cylindrical stems of other species of the genus, but has been destroyed in our

Diameter of the hollow axis, .16 below, .19 above ; diameter of verticils, more than three
inches ; number of cells in one tenth of an inch, 6 to 8.

Much remains to be learned of this coral ; and we desire to direct attention to it by
making known, in the mean time, its very extraordinary ensemble. The two species of
Cladopora described by us not only present unique characters in their general forms, but,
in their structure, furnish us with the proofs that Cladopora is a generic type founded in

Cladopora fibrosa Hall. Pal. N. Y., II. 139, pi. xxxviii. figs. 4, 5.

Cladopora seriata Hall. Pal. N. Y., II. 137, pi. xxxviii. fig. 1.

Cladopora reticulata Hall. Pal. N. Y., H. 141, pi. xxxix. fig. 3. We have specimens of
this exhibiting the reticulations spread over a surface eight or ten inches square.

Halysites catenularia Linn. sp. Seldom found in a recognizable state of preservation. We
occasionally find casts of the spaces enclosed by the labyrinthine walls, which, with the
vertical striations and transverse wrinkles of the tubes preserved, present an object closely
resembling the enigmatical fossil named Cophinus diibius in the Silurian System, (pi. xxvi. fig.
12,) and which in the Siluria (p. 136, and pi. xv. fig. 4) is attributed to the slow gyration of
the stems of encrinites after the mud had settled around them. The Ludlow fossil may clear-
ly have had the origin attributed to it; but our specimens, though at first obscure, have
furnished, at length, conclusive evidence of being the impressions or casts of the walls of a
Halt/sites. The transverse dissepiments in some of the cells are well preserved and numerous.

Siromatopora sp ? We have a weathered specimen, exposing the stellately diverging
ramulets formed in the interlaminar spaces. This curious organism would not ordinarily
be identified as a Stromatopora ; but, by the aid of Dr. Rominger's extensive suite of specimens
of this genus, its true character becomes apparent. There is a specimen of the type, which
shows stellate cell-mouths, in the Illinois State Cabinet. This is in the usual state of pres-
ervation, and may be identical with ours, though we have only had the opportunity to give
it a hasty glance.

Stictoporapunctipora? Hall. Pal. N. Y., II. 157, pi. xl. B, fig. 2 a-c.

Polypora incepta ? Hall. Pal. N. Y.,II. 167, pl.xl. D,fig. 5 -/. A large undulately cyathi-
form frond, nearly six inches in diameter, with fenestrules somewhat smaller than in the
typical species. The cells have not been certainly distinguished either in this or the fol-
lowing species.

Fenestella elegans? Hall. Pal. N. Y., II. 164, pi. xl. D, fig. 1 a-g.

Lwhenalia concentrica Hall. Pal. N. Y., II. 171, pi. xl. E, fig. 5, a-g.


Ischadites tessellatus W. and M.

Plate II. figure 3.

Body somewhat tapering, pyriform, compressed on the side toward which the smaller end
is slightly inflected ; the larger end imperfect in all our specimens. One example is some-
what in the form of a triangular prism with rounded edges, and the sides indented toward


the base, while the upper end is convex. The whole exterior is divided into small rhomboidal
or nearly square areas by ridges which originate at the apex and describe curves obliquely
approaching the base, and crossing each other like the curves of the " engine-turned
ornament of a watch." In the best preserved specimens, these ridges are surmounted by
little crests deepening the pits or cells which they mark out. In other specimens these
cells are simply hopper-shaped cavities. The cells of course increase in size from the ori-
gin of the ridges to that part of the surface where the diameter of the body is great-
est. In the bottom of each cell is a small pore penetrating the internal cavity. Besides
this, each cell communicates by pores with the four neighboring cells touching it at the
angles. These connecting pores are parallel with the general surface, and pass under the
intersection of the two crests or ridges. Each rectangular intersection, therefore, rests over
the crossing of a couple of right-angled passage-ways. In some specimens, in which the
hopper-shaped cells are shallow, these pores, extending across the cell from corner to corner,
present the appearance of open passage-ways excavated through the substance of the test ;
on the side toward the larger end of the body, however, the passage-way remains covered.
In such cases, the feature which first strikes the eye is a pair of furrows intersecting each
other at right angles in the middle of each cell, forming three sides of a cross.

Our specimens are all casts, and exhibit no further internal structure, except that the
central pores can be seen penetrating the internal cavity, and losing themselves at the
depth of a quarter of an inch. Polished sections at right angles with the surface present
obscure indications of sac-like cells extending inward from the surface about one fourth
of an inch. There is one of these on each side of the central pore, and the inner end
of the cell is regularly rounded. The pore seems to have been the means of communi-
cation between the inner common cavity of the body and the external element. It was
perhaps respiratory in its function. The cells present the appearance of individualization,
while the entire body was undoubtedly a compound organism. Polished surfaces at right
angles with the larger axes of these cells do not succeed in bringing their walls into view.

No peduncle of attachment appears to have been in connection with the smaller end ; but
the larger ends are all imperfect, and it seems not unlikely that this end was adherent, or
possibly pedicled.

The largest and most perfect specimen is 2.5 inches in length, with a maximum diameter
of 1.75 inches. The diameter of the cells over the most swollen portion of the body is .09

These very interesting and beautiful specimens are evidently congeneric, if not conspecific
with I. K&nigi Murchison, 1 and I. canadensis Billings, (Geol. of Canada, pp. 309, 327,) though
the entire form of I. canadensis has not been figured, and I. Komigi is less attenuate at the
smaller end. We are of the opinion, also, that they possess close relations with Dictyocrinus
Conrad, and Tetragonys Eichwald; and that all these genera belong to the same zoological
type as Reccptaculites, which has been shown by Salter to be one of the Foraminifera, as D. D.
Owen conjectured in 1844. At least, the affinities of Ischadites with Receptaculites seem to
be pretty clearly shown by our specimens ; and it is worthy of remark that Morris, in his
Catalogue, has united I. Kwnigi and Receptaculites Neptuni, while Professor Hall says, (Pal.
N. Y., HI. p. 148) : " The figures [of I. Kceniyi] in the Silurian System bear so close a resem-
blance to Receptaculites that I could scarcely regard them as distinct from that genus."

1 Silurian System, 697, pi. xxvi. fig. 11 ; Siluria, pi. xii. fig. 6.



Actinocrinus obpyramidalis W. and M.

Plate II. figure 4.

Body pentangularly obpyramidal ; radial series standing out in salient angles with
depressions between, deepening upward, and giving great prominence to the arm bases,
which are quite small, and exist in pairs. Dome arched, with the appearance (in our speci-
mens) of a broken proboscis a little nearer the centre than the anal side.

Basal plates not seen ; radials three, the two lower hexagonal, the first a little larger than
the other two, and having its upper side shortest ; the third radial heptagonal, supporting a
pair of hexagonal secondary radials upon its upper sloping faces. The other plates of the
cup cannot be satisfactorily defined in our specimen. They give evidence of having been
elevated and sculptured. We have seen a specimen 1.75 inches high to the top of the dome.

This species has all the general appearance of an Actinocrinus, and resembles such Carbon-
iferous species as A. quinquelobus and A. cornigerus ; and was not improbably furnished, like
them, with spines upon the dome. We know of no allied species of the same geological

MEGISTOCRINUS Owen and Shumard.

Megistoerinus Marcouanus W. and M.

Plate II. figure 5.

a. Left antero-lateral ray. b. Left postero-lateral ray.

c. Azygos side, with one half of the azygos interradials.

1 Learning, after we had engaged in this investigation, that our own specimens of that type should be worked up by him.

Mr. W. H. Niles, of the Museum of Comparative Zoology He has, however, insisted on our proceeding independently ;

at Cambridge, was occupied in a reinvestigation of Crinoi- and, having done so, we deem this statement demanded by the

dea with a view to publication, we should have preferred that courtesy which ought to prevail among co-laborers in science.


Body large and massive, somewhat obconic, spreading more rapidly towards the arm
bases ; base sub-acute, generally turned to one side. Basal plates three, equal, hexagonal
the inner side very short a little broader than high. Radials three in each series. Of
the first radials three stand opposite the three basals, and are hexagonal, a little higher than
wide, the upper side being shortest, the lower next in length. The other two first radials
stand opposite the division between two basals ; they are heptagonal by the division of the
base, the two basal sides, however, lying nearly in the same straight line. The second ra-
dials are hexagonal, nearly as large as the first, one fifth longer than wide, the upper and
lower sides about half the length of the others. The third radials are larger than the sec-
ond, octagonal in the anterior and antero-lateral rays, having two upper sides, each of
which is about equal to the lower one, the lateral sides being considerably the longest,
and thus causing this plate to be longer than broad ; in the postero-lateral rays they are
heptagonal by the enlargement of the anal plates. The first supraradial plates are irreg-
ularly heptagonal, two thirds as large as the third radial. Second supraradials heptagonal or
octagonal, of the same size as the first or smaller, supporting on their upper sloping sides a
pair of small pentagonal brachials. Number of arms twenty. First regular interradial hexa-
gonal, nearly as large as the first radials, supporting on its shorter upper sides a pair of
smaller interradials, which are succeeded by about ten other interradials, making thirteen
in all. The azygos, or anal interradials number about thirty. The first rests upon the
basals, and has precisely the same form and size as the antero-lateral first radials ; like the
radials, also, it is succeeded by two others, producing a series resembling the true rays, dif-
fering, however, in the plates, being a little smaller than the true radials, and being suc-
ceeded by five other smaller plates nearly in the same line. Between this series of anals
and each contiguous ray lies a series of three plates followed by two pairs. First inter-
supraradial hexagonal, surmounted by two pairs of smaller ones. The formula of this spe-
cies is, therefore, as follows :

Basals 3

Radials 3X5= 15

Supraradials 2X2X5= 20

Brachials 2X2X2X5= 40

Regular Interradials 13X4= 52

Azygos Interradials 30

Inter-supraradials 5x5= 25


Total plates in the cup 185

One of our specimens is 3.4 inches long, to the bases of the arms. Another one, defec-
tive below, has a diameter of three inches at the bases of the arms ; most of the specimens
are not over half this size.

There is a variety of this species (apparently) which is marked by ridges along the
series of radials and secondary radials. These ridges (in casts) are not interrupted by the

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Online LibraryAlexander WinchellEnumeration of fossils collected in Niagara limestone at Chicago, Illinois ; With descriptions of several new species → online text (page 1 of 5)