dron (fig. 747), Quercus, Cornus, Fagus, Populus, Salix (fig. 749), Alnus,
Platanus, Sassafras {fig. 746), Liquidambar, Taxodmm, etc. These spe-
cies have been collected in New Jersey, Alabama, Nebraska, Kansas,
New Mexico, and Vancouver's Island on the Pacific (Newberry), and
mainly from the earliest or Dakota group.
Besides Angiosperms, there were also thej^r^^ of the Palms. It is,
however, still questioned whether any American Cretaceous speci-
mens of this tribe have been found. Fossil palm-leaves of the fan-
palm kind (genus Sahal) are met with on Vancouver's Island, in
deposits which have been pronounced to be Cretaceous.
Fig. 746, Sassafras Cretaceinn Newberry, from the Dakota group, along
with the three following (Meek & Hay den) : fig. 747, Liriodendron Meekii
Figs. 746-749.
Angiosperms (or Dicotyledons). ā Fig. 746, Sassafras Cretaceum ; 747, Liriodendron Meekii ;
748, Leguminosites Marcouanus; 749, Salix Meekii.
Heer; fig. 748, Leguminosites Marcouanus Heer ; fig. 749, Salix 3feekii
Newberry.
472 MESOZOIC TIME REPTILIAN AGE.
Large stumps of Cycads have been found in Maryland near Baltimore ; one is
12 inches in diameter and 15 high. (P. T. Tyson, who observes that they may
be Upper Jurassic.)
2. Animals.
Among Protozoans, the group of Rhizopods has a special im-
portance in the Cretaceous period. Tliey are abundant in many
of the beds in New Jersey and other Cretaceous regions of North
America, though less so than in the chalk beds of Europe. In one
genus, OrbitoUna, the species are disk-shaped (fig. 750), and closely
resemble in form some of the Nummulites of the early Tertiary.
Sponges also are a common fossil, although little known thus far
in America.
In the sub-kingdom of Mollfisks, the more characteristic genera
of Conchifers are the three of Oysters, Ostrea (fig. 753), Gri/phcca
(figs. 755, 75G), and Exogyra (fig. 754) (species of which occurred
in the Jurassic period, but are more common and larger in the
Cretaceous), and Inoceramus (fig. 757), a genus related to Avicula
and Mytilus, some species of which are of great size and have the
surface in undulations. Exogyra and Inoceramus end with the Cre-
taceous, and but one Gryphcca is known afterward
Another group characteristic of the Chalk period, and, moreover,
not known after it, is that of the PaaUstes (figs. 782-784). It includes
the genera Hlppuriies, RadloUtcs, SphcruUtes, and a few others. Hip-
puritcs has a long tajDering form (fig. 782), somewhat like a nearly
straight, but rude, horn with a lid on the top, the lid being the
upper valve, and the conical portion the lower. "Within there is
a subcylindrical, tapering cavity, having one or more projecting
ridaes on the sides running; the whole length. Fiir. 782 a shows the
interior of one : there are tw^o prominent ridges, but one is only
partly free in the interior space. The other genera have a similar
anomalous character, but differ in the interior. Fig. 783 repre-
sents the lid or upper valve of a RadloUtcs, showing the projections
below [h, c) to which the muscles closing the lid are attached; and
fig. 784 is the same in Spherulites. The Rudistes are supposed to be
related to Chama among the Dimyary MoUusks.
Of Ccphalopods, there are in tlie Cretaceous beds numerous Am-
monites and Belemnites. Some of the Ammonites from beyond the
Mississippi, are over three feet in diameter. There is also a multi-
plication of other genera of the Ammonite family, the shells of
which are like Ammonites more or less uncoiled ; as Scaphitcs (figs.
7GG, 7G7), I'rom scapha, a boat; Crioceras (fig. 78G), from Kpiog, a ram^s
horn; Ancyloceras (fig. 787), from ayKvl-q, a hook or handle; Hamites,
CRETACEOUS PERIOD. 478
(fig. 788), from hamus, a hook; Toxoceras (fiig. 789), from ro^ov, a bow;
BacuUles (fig. 708), from hacidum, a walking-stick . Turrilitcs (fig.
790) is another form, unlike other Ammonitids in being a turreted
spiral. Another genus resembles an opened spiral, and is called Heli-
coceras. Among these genera, only Ammonites, iScaphites, Anq/loceras,
Hamites, Ptychoceras, BacuUtes, Turrilites, and Ilclicoceras, have been
found in American Cretaceous rocks. Baculiies ovatus (fig. 768)
attains a length of a foot or more, and a diameter of 2\ inches,
and Scaphites Conradi (fig. 7GG) a length of six inches. Ancyloceras
and Toxoceras occur first in the European Jurassic.
Among Vertebrates, there is the first appearance of several pro-
minent modern groups, marking grand steps of progress in the
life of the world.
1. Common or Osseous Fishes, or Teliosts, ā the tribe which includes
nearly all fishes, excepting Ganoids and Sharks, and, consequently,
nearly all edible si)ecies. Their distinguishing characteristics are
mentioned on page 278.
2. Trite Crocodiles, in the class of Reptiles.
3. Cetaceans or Whales, in the class of Mammals.
Besides these marks of progress, there are many other new
genera of Fishes and Reptiles.
The Squalodonts, or modern tribe of Sharks having teeth with
sharp cutting edges, besides other peculiarities, are greatly multi-
plied. The new tribes do not displace the Oestracionts and Ga-
noids, which continue to be common until the close of the Creta-
ceous period, and still have some representatives.
Figs. 772, 773, represent some of the Sharks' teeth. Fig.
773 are pavement-teeth of a fish of the old Cestraciont group,
pertaining to the genus Pii/chodus, characteristic of the Cretaceous
period.
Beyond the Mississippi, remains of Reptiles have been found,
and both there and in New Jersey bones of a colossal Lacertian
Reptile of the genus Mosasaurus. These Reptiles are supposed to
have been web-footed and aquatic in habit, while at the same time
carnivorous. The tail was flattened, long, and powerful, and thus
fitted for sculling through the water. The New Jersey species was
24 feet long. Another large Rej^tile, Hadrosaurus Foulkii Leidy, is
related to the Iguanodon of the Wealden, and was probably 25
feet long; its remains were found near Haddonfield, N.J.
Bones of Whales also occur in the New Jersey Cretaceous. They
are the earliest species yet discovered of this tribe of Mammals.
474
MESOZOIC TIME ā REPTILIAN AGE.
Characteristic Species.
1. Protozoans. ā RMzopodn. ā TextUarid MUsonHensis, T. glohulosn, Pha-
nerostomum senarium, Rotalia lenticuliiia, R. senaria, Grammostomum phyllodes,
Figs. 750, 751 A, B.
51 A
51 B
Rhizopod.ā Fig. 750, Orbitolina Texana. Brachiopods.ā Fig. 751 A, Terebratulina plicata;
751 B, Terebratula Ilarlani.
from the Cretaceous of the Upper Missouri, identified by Ehrenberg; Cristel-
laria rotidato, Dentcdina jndchra Gabb, etc., from New Jersey; iig. 750, Orbito-
lina Texana Roemer, from Texas, a species having the form of a disk, slightly
conical.
2, Radiates. ā (o.) Polyp- Corals. ā Astrocoenia Sancti-Sahee Roemer, Texas,'
Montlivaltia Atlantica, New Jersey, etc.
{h.) Echinodermn. ā Holaster simplex; Ananchytes cinctus, Toxaater elegans ;
also species of Diadema, Hemiasler, Holecti/pus, Ci/phosonia, etc.
3. Mollusks. ā (a.) Bnjozoans. ā Numerous species have been described
and figured by Gabb & Horn, of the genera Memhranijyora, Fhistrella, Eseha,-
I'ipora, Biflustra, etc.
{h.) Brachiopods. ā Fig. 751 A, Terebratulina plicata ; fig. 751 B, Terebratida
Harlani iMorton, from New Jersey; Linrjida nitida M. & H., Nebraska.
(c.) Conchi/ers. ā Fig. 753, Oxtrea Larva Lamarck, found also in Europe; 0.
conyesta Conrad, from Arkansas and Nebraska ; fig. 752, Exoyt/ra arietina
Roemer, from Texas; fig. 754, E. costata Say, from the Cretaceous of the Atlan-
tic and Gulf borders; fig. 755, Gryphxa vesicnlaris Lamk., at nearly all North
American localities, and also a European species ; fig. 756, G. Pifcheri Morton,
from Cretaceous region west of the Mississippi River; fig. 757, Inoceramns ])ro-
blematicus Schlotheim, from west of the Mississippi, and also a European species.
Among Rudistes, Radiolites Anstinensis Roemer, a species five to six inches
in diameter, from Alabama, Mississippi, and Texas; Radiolites lamellosus
CRETACEOUS PERIOD.
475
Tuomey, from Alabama j Hipinirites Texanus Roemer, a species eight inches long
and four in diameter, from Texas; Cnprotina Tcjcana Roemer, from Texas.
Figs. 752-757.
CONCHIFERS.ā Fig. 752, Exogyra arietiiia; 753, Ostrea Larva; 754, Exogyracostata; 755, Gry-
phaea vesicularis; 756, G. Pitcberi; 757, Inoceramus problomaticus.
Figs. 758-764.
61
Gasteropods. ā Fig. 758, Fiisus Newberryi; 759, -Fasciolaria buccinoides; 760, Aporrbais
Americana; 761, Margarita Nebrascensis ; 762, Nerinjea Texana; 763, 764, Bulla si)eciosa.
476
MESOZOIC TIME ā REPTirJAN ACJE.
Fi^s. 765-770.
65 6
Cephalopods.ā Figs. 765, 765 a, 765 b, Ammonites Placenta; 766, Scaphites Conradi; 767, S.
larva^foi-niis; 7G8, 768 a, Baculites ovatus; 769, Section of B. compressus, reduced; 770,
Nautilus Dekayi.
CRETACEOUS PERIOD.
477
(d.) Gmtero2-)ods. ā Fig. 758, Fusns Neichernji M. & H., from Nebraska; fig. 759,
Fasciolan'a hxiccinoides M, Ā«& H., from Nebraska; fig. 760, Apovrhais Americana
{=^ Rostellaria Americana) Evans & Shumard, from Nebraska; fig. 761, il/a> -
garita Nebrascensis M. & H., from Nebraska; fig. 762, Ncriniea Texana Roemer,
from Texas; ^V. Acus Roemei', from Texas; figs. 763, 76J:, Bidla speciosa
M. & H., from Nebraska.
(e.) Cephalojiods. ā Fig. 765, Ammonites Placenta Dekay, from Atlantic border.
Gulf border, and Upper Missouri, young specimen, natural size; fig, 765 a, out-
line side-view of the same, reduced; fig. 765 6, one of the septa of the same,
natural size; fig. 766, Scaphites Conradi Morton, from the same localities as pre-
ceding; fig. 767, S. larvseformis M. & H., from Nebraska; fig. 768, Baciditea
ocatuH Say, from New Jersey ; fig. 768 o, outline of section showing oval form;
tig. 769, outline of section of i?. compressus Say, Upper Missouri; fig. 770, Nau-
tilus DcJcayi Morton, from the Atlantic and Gulf borders, and west of the
Mississippi from Texas to Upper Missouri, and also reported from Europe,
Chili, and Pondicherry in the East Indies. Fig. 771, Belemnitella mucronata
Schlotheim, same U. S. distribution as preceding.
Fig. 771.
Cephalopod. ā Belemnitella mucronata.
4. Vertebrates. ā [a.) Fishes. ā Fig. 772, Otodus appendicidaUis, from New
Jersey. This genus Otodus (of the tribe of Squalodonts) is near Carcharodou,
Figs. 772, 773.
Squalodont Selachian. ā Fig. 772, Otodus appeiuliculattis. Cestraciont Selachian.
Figs. 773, 773 a, Ptycliodus Mortoni.
but the teeth have a smooth margin without denticulations. Oxyrhina, an-
other genus of this period, is like Otodus in this respect, but wants the small
lateral teeth a, ā¢Ā«. There were also species of Lamna, the teeth of which are
478
MESOZOIC TIME ā REPTILIAN AGE.
narrow, as in fig. 465, page 277. Figs. 773, 773 a, different views of a tooth
of Ptychodns 3/o/ioni (Cestraciont), a species found in New Jersey.
(h.) Reptiles, ā 3fo8asauius Maximiliani Goldfuss, from New Jersey, a species
24 feet long : a fine specimen of the cranium is in the Museum at Bonn in
Prussia. Fig. 774, Crocodilus clavirostrw Morton, from New Jersey : whole
Fig. 774.
Crocodilus clavirostris ( X %)ā¢
length of skull (in specimen) 23 inches, greatest breadth 12J inches. Owen
has named two other New Jersey Crocodiles, C. hasijissus and C. basitnmcatns.
Remains of the Geoaaur, according to Morton, occur in New Jersey ; also bones
of Turtles.
(c.) 3fammals. ā Cetaceans. ā Priscodelpliinus grandseviis Leidy, and P. liar-
lani Leidy, both from New Jersey.
III. Fossils characteristic of the Subdivisions of the Creta-
ceous.
A. Earlier Cretaceous. ā No. 1 (Dakota group). Upper Missouri: Pha-
rellaf Dakotensis, Axinpea Siouxensis, Cyjirina arenaria, Leaves of Anrjio-
sperms, Alabama: Ceratites? Americanus Harper, Leaves of Awjiosperma,
New Jersey : Leaves of Angiosperms.
No. 2 (Benton group). Upper Missouri: Inoceratmis prohlematicns, J, um-
honatns, Ostrca eongesta, Pholadomya jiapyracea, Ammonites percarinatus, A.
vespertinns Morton ( = A. Texanus Roemer), Scaphites larvseformis. Texas:
Ammonites jjercarinatns, Tnoceramus CajJitliis. New Jersey : none.
No. 3 (Niobrara group). Upper Missouri: Ostrca congesta, Inoceramns pro-
hlematicus, I. aviculoides, I. pseudo-mytiloides. Arkansas : To.raster elegans,
Holaster simplex, Cardium multistriatum, Inoceramns prohlematicns, I. co)ifertim-
annulatits, Grypheea Pitcheri. Texas: Holaster simplex. Epiaster elegans, Oidarts
hemigranosus, GrypJiiea Pitcheri, Ostrca snhovata (0. Marshii Marcou), Inoceramns
prohlematicns, Turrilites Brazoensis, Ammonites Texanus, Hamites Fremonti.
New Jersey : none.
CRETACEOUS PERIOD. -179
B. Later Cretaceous. ā X(Ā». 4 (Pierre group). Upper Missouri: Nautilus
Delcayi, Ammonites Placenta, A. co>i>ple.rus, Baculites ovatus, D.compressuH, Heli-
(oceras Mortoni, Inoceramus subleriii, Jfof<af<auru>i ^Uissoun'oisis. Alabama:
In bed a, Teredo tibialis?; in bed b, E.votji/ra costata, Grijpheea vesiculan's,
Inoceramus biformis, Pecten b-costatus, Nautilus Dekayi, Ammonites Placenta,
A. Delaicarensis, Baculites ovatus; in bed c, Ostrea Larva, GryiiJisea lateralis
{Gc.YovaQv), Neithea Mortoni. New Jersey : Bed a, Ammonites Placenta, Bacu-
lites ovatus ; bed b, Amm. Delaicarensis, A. complexus, Baculites ovatus. Nautilus
Dekayi, Belemnitella mucronat<( ; bed c, Terebratulina pUcata, Pholadomya
occidentalis, Ostrea Larva, Gryphsca vesicularis, Exoyyra costata, bones of Jlosa-
saurits.
No. 5 (Fox Hills group). Upper Missouri : Nautilus Dehayi, Amm. Placenta,
A. lobatns, Sca2)hites Conradi, Baculites ovatus, Jffosasaurus Missouriensis.
Alabama: Exocjyra costata, Gryphica vesicularis, Nautilus Dehayi, Baculites
ovatus, Scapfiites Conradi. New Jersey : Jfontlivaltia Atlantica, Nucleolites
crucifer, Ananchytes ductus, A. fimbriatus, Terebratula Harlani, Gryphsea lateralis,
G. vesicularis, Neithca Mortoni.
The New Jersey region abounds in Oysters and Exogyrse, has some Ammonites,
Baculites, and Echinoderms, but no Hippurites or Caprinse.
The Upper Missouri has very few Oysters, no Exo<jyrse, many and large Am-
monites and Baculites, but one rare Echinoderm {Hcmiastcr Humphreysiamis), no
Brachiopods, except two Lincjulfr, and no Hi^ipurites or Caprinse.
The Alabama resembles the New Jersey, and the Arkansas the corre-
sponding or middle beds of Nebraska and upper of New Jersey; but both con-
tain Hippurites and Echinoderms.
The Texas region has but few species in common with the others, ā Ammonites
vespertinux, Inoceramus latus?, and/. Barabini, the latter being still questioned;
and it is characterized by Hippurites, Caprinse, Neriuscsc, etc., like the Upper
Chalk of southern Europe.
The species common to Nebraska and New Jersey, according to Meek & Hay-
den, are Nautilus Dekayi, Scaphitea Conradi, Ammonites Placenta, A. complcxus,
A. lobatus, Baculites ovatus, and Amauropsis jxd^dinsp/ormis.
2. FOREIGN.
I. Rocks : kinds and distribution.
The Cretaceous formation spreads across England just east of the
line of the Jurassic, extending north-northeastward from near Port-
land on the British Channel to Cambridge, and then northward to
Flamborough Head on the German Ocean. Like the Jurassic,
again, it reappears in northern France across the British Channel.
It also occurs in other parts of France, in Sweden, and in southern,
central, and western Europe.
The rocks are (1) /Sandstone, generally soft, and of various colors;
(2) Marly or clayey beds ; (3) the variety of limestone called
Chalk, the common writing-material, in beds of great thickness ;
480 MESOZOIC TIME ā REPTILIAN AGE.
(4) other limestones, either loose or compact. Among the sandy-
portions the Green-sand beds are a marked feature, especially of
the lower part of the formation. This is so eminently the fact
that the Lower Cretaceous in England is called the Green-sand,
although only a part of the layers are green, and in some regions
none at all.
The Chalk often contains Jlini in nodules, which are distributed
in layers through it like the hornstone in the earlier limestones.
They are more or less rounded, and often assume fantastic shapes.
Sometimes they resemble rolled stones ; but in fact all are of con-
cretionary origin. The exterior of the nodules for a little depth
is frequently white, and penetrated by chalk, proving that they are
not introduced boulders or stones, but have originated where they
lie. Moreover, many chalk fossils are turned into flint, and it is
common to find a mass of flint w^ith a fossil as its nucleus.
The Cretaceous beds of Europe have been divided into ā
1. The Lower Cretaceous, including in England the Lower Green-sand, 800
to 900 feet thick, and in other regions beds of clay, and limestone sometimes
chalky.
2. The Middle Cretaceous, including in England (a) the clayey beds or marls
called Gaidt, 150 feet thick, and [h) the Upper Greeii-saiid, 100 feet.
3. The Upper Cretaceous, including in England the beds of Chalk, in all about
1200 feet: it consists of (a) the Lower or Gray Chalk, or Chalk Marl, without
flint; {b) theWhite Chalk, containing flint; (c) the Mae8f)-icht beds, rough friable
limestone at Maestricht in Denmark, 100 feet thick.
The subdivisions of the Cretaceous are variously named in diff"erent parts of
Europe.
Loioer Cretaceous. ā Superior Neocomian of D'Orbigny (the Wealden being
the inferior) ; also his Aptian ; the Hils-conglomerat of Germany.
Middle Cretaceous. ā 1. Gault, Albian of D'Orbigny, LoAver Planerkalk of
Saxony. ā 2. Upper Green-sand, Cenomanian of D'Orbigny, Lower Quadersand-
stein of the Germans.
Upper Cretaceous. ā 1, Gray Chalk, or Chalk without flints, Turonian of
D'Orbigny, Hippurite Limestone of the Pyrenees, Ujiper Planerkalk of Saxony.
2. White Chalk, or Chalk loith flints, Senonian of D'Orbigny, Upper Quader-
sandstein? of the Germans, La Scaglia of the Italians. 3. Maestricht beds,
Danian of D'Orbigoy, Calcaire pisolitique near Paris.
In North America the Earlier Cretaceous corresponds, according to Meek &
Hayden, to the inferior division of the Upper Cretaceous of Europe, or the Gray
Chalk, with perhaps part or all of the Middle Cretaceous; and the Later Creta-
ceous, to the superior division of the Upper Cretaceous, or the White Chalk.
In mineral character the beds of each division vary much over Europe, the
Chalk of England being synchronous with marls and solid limestones in Europe.
The Cretaceous of Great Britain is not found on any part of the Atlantic
coast, excepting a small area in the vicinity of the Giants' Causeway. The beds
of northern France spread eastward over Belgium and Westphalia, but not to
CRETACEOUS PERIOD. 481
the Atlantic on the west; but farther south they occur at the deep indentation
of the Bay of Biscay. They cover part of the Pyrenees, and reach into Spain
in what has been called the Pyrenean basin, which in the Cretaceous period was
a bay on the Atlantic. There is another sea-border deposit at Lisbon, in Spain.
In southern France, over what is called the Mediterranean basin, the beds ex-
tend from the Gulf of Lyons along the Mediterranean coast, northeast to Swit-
zerland, though with interruptions. The formation is found in the Juras and
Alps, in Italy, Savoy, Saxony, Westphalia and Bohemia, northern Germany,
Poland, middle and southern Russia, Greece, and other places in Europe. In
Asia it has been observed about Mount Lebanon and the Dead Sea, the Cauca-
sus, in Circassia and Georgia, and elsewhere ; in northern and southern Africa ;
in South America, along the Andes, and on the Pacific coast, occurring in
Venezuela, in Peru, at Concepcion in Chili, in the Chilian Andes at the passes
of the Portillo and Rio Volcan at an elevation of 9000 to 14,000 feet, in the
Straits of Magellan at Fort Famine in Fuesia.
"o^
II. Life.
The Life of the Cretaceous period in Europe resembled that of
America, but was far more abundant. Nearly 6000 species of ani-
mals have been described, more than half of them MoUusks ;
whereas in America the whole number does not exceed 2000.
1. Plants.
Angiosperms and Palms were growing in Europe, and among the
former there were the Willow, Walnut, Maple, and Holly. But
the relics of F'erns, Conifers, and Cycads greatly preponderate ; for
the Cretaceous was properly the closing part of the era of Cycads.
Vegetable remains of all kinds are rare, as the deposits are marine.
The microscopic Protophytes called Diatoms and Desmids are
found in some of the beds, especially in the flint of the Chalk.
The former have siliceous cases, as explained and illustrated on
p. 271, and they may have contributed, as has been suggested, to
the material of the flint nodules. The Desmids are not siliceous,
but are still very common in the flint, ā far more so than Diatoms
(which are rare) : the kinds which have been called Xanthidia are
especially abundant ; their forms are very similar to those from
the Devonian hornstone figured on p. 271.
2. Animals.
The Protozoans of the family of Rhizopods (p. 163) appear to have
been among the most important rock-making species of the Creta-
ceous period ; for it is supposed that the Chalk itself is to a large
extent made of their shells. According to Ehrenberg, a cubic inch
32
482 MESOZOIC TIME ā REPTILIAN AGE.
of chalk often contains more than a million of microscopic organ-
isms, among which far the most abundant are these Rhizopods
(called also Foraminifera and Polythalamia). Some of the species
are represented in figs. 778-781.
The Sponges, also, were of great importance in the history of the
Cretaceous rocks. They occur cup- or saucer-shaped, tubular,
branched, and of other forms. One is figured in fig. 777. Their
^ % ^ "7^
Spicula of Sponges.
siliceous spicula are common in the flint, and have contributed, as
well as Diatoms, towards the silica of whicli it was made.
Among Radiates, the Corals and Echinoids are mostly of modern
types, and are far more numerous than in the Cretaceous of
North America.
The same genera of Mollusks abound that are enumerated on
p. 472. But the variety of Brachiopods, Gasteropods, and Am-
monites is vastly greater than on the American continent. The
Ammonites, and the uncoiled forms of the same family mentioned
on p. 472, are particularly abundant. One English Ammonite
(the A. Lewesiensis), from the Lower Chalk, has a diameter of a
yard.
The genera of Gasteropods are to a greater extent modern
genera than in the preceding period, and the proportion of siphon-
ated species (having a beak) is nearly as great as in existing seas.
The Rudistes (figs. 782-784) are very common in southern Europe
and Asia Minor, and about eighty species have been described ; only
a single species ā RadiolUxs Mortoni ā has been found in England.
In the sub-kingdom of Vertebrates, there are Fishes of the mo-
dern order of Teliosts, and Sharks of the modern tribe of Squalo-
donts, as stated with regard to America (p. 473). One of these
new fishes of the former group is shown in fig. 791. The Salmon
and Perch families are represented among these earliest of Teliosts.
Cestraciont teeth are very common.
The class of Reptiles in the earlier part of the Cretaceous period
included the Iguanodon ; both then and later there were three or
iour Plesiosaws ; an Ichthyoscu(r ; another swimming Saurian, called
Polyptychodon by Owen, nearly 50 feet long ; several Pterodactyls, one
of which, the P. giganteus, was 6 to 7 feet in the spread of its
wings ; a Mosasaur, 25 feet long (fig. 792) ; some Turtles. No true
CRETACEOUS PERIOD.
483
Crocodiles have been reported from the European Cretaceous beds,
the earliest occurring in the Tertiary.
No remains of Birds or Mammals have yet been discovered.
Fig. 777.
Characteristic Species.
1. Protozoans. ā (o.) Sponges. ā Fig. 777, Siphonia lohnta, from the Chalk.
Figs. 776 a to 776 h represent the siliceous spicula of Sponges, showing some
of the various forms they present. Over
one hundred species related to Sponge occur
in the Cretaceous strata of England. Scyj}hia,
Spougia, and Ventriculites are the more
common genera among the twenty enume-
rated.
(6.) Jihizopods. ā Fig. 778, Lituola nautiloi-
dea. Fig. 779, Flabellina rugosa ; fig. 779 a,
profile of same. Fig. 780, Chrysalidina gra-
data. Fig. 781, Cuneolina Pavonia ; fig. 781 o,
profile of same. All are much magnified, the