
- Parr III. Sxor. iii. §1.] CRETACEOUS. 811 
- aremarkable elongation of form, particularly in the tail; their heads 
_ were large, flat, and conic, with eyes directed partly upwards. They 
swam by means of two pairs of paddles, like the flippers of the whale, 
and the eel-like strokes of their flattened tail. Like snakes they 
had four rows of formidable teeth on the roof.of the mouth, which 
_ served as weapons for seizing their prey. But the most remarkable 
feature in these creatures was the unique arrangement for permitting 
them to swallow their prey entire, in the manner of snakes. Each 
half of the lower jaw was articulated at a point nearly midway 
between the ear and the chin, so as greatly to widen the space 
between the jaws, and the throat must, consequently, have been 
loose and baggy like a pelican’s. The deinosaurs were likewise well 
represented on the shores of the American 
waters. Among the known forms are Hadro- 
saurus, a creature like the Iguanodon, and 
about 28 feet long; Lelaps, of about equal 
dimensions, resembled the Megalosawrus, hay- 
ing massive hind feet on which it could pro- 
bably erect itself. Still more gigantic was 
the allied Ornithotarsus, which is supposed 
to have had a length of 35 feet. Pterosaurs 
have likewise been obtained characterized 
by an absence of teeth (Pteranodonts), and 
some of which had a spread of wing of 20 
‘to 25 feet. Among the Chelonians one gi- 
gantic species is supposed to have measured 
upwards of 15 feet between the tips of the 
flippers. 
The remains of birds have been met 
with both in Hurope and in America among 
Cretaceous rocks. From the Cambridge Fic. 397. — Creraczous 
Greensand bones of at least two species, re- ae Sane 
ferred to the genus Enaliornis, have been % Ji (1.4 Tooth, upper 
obtained. These creatures are regarded by jaw @). 
Professor Seeley as having osteological cha- 
‘racters that place them with the existing natatorial birds." But 
among the most remarkable fossil avian remains yet found are those 
of the Odontornithes, or toothed birds, from the Cretaceous beds of 
Kansas. Professor Marsh, who has described these interesting and 
wonderfully preserved forms, points out that in one of the genera,’ 
named by him Hesperornis, the jaws were furnished with teeth im- 
planted in a common alveolar groove, as in Ichthyosaurus; the 
wings were rudimentary or aborted, so that locomotion must have 
been entirely performed by the powerful hind limbs, with the aid of 
a broad, flat, beaver-like tail, which no doubt materially helped in 

1 Q. J. Geol. Soc. 1876, p. 496. 
2 “ Odontornithes,” being vol. i. of Memoirs of Peabody Museum of Yale College, and 
also vol. vii. of Geol. Hxplor, 40th Parallel. 
