MEDIEVAL OR ME80ZOIC TIMES. 191 



" The head was a few inches longer than that of a grizzly bear, 

 and the jaws even deeper in proportion to the length. The muzzle 

 was shorter and deeper than that of a bull-dog. The teeth were 

 long- cylindrical fangs, smooth, glistening, and of irregular size. 

 At certain points in each jaw they projected three inches above the 

 gum, and were sunk one inch into deep pits, being thus as long as 

 the fangs of a tiger, but much more slender. Two pairs of such 

 fangs crossed each other on each side of the end of the snout." Six 

 species of these rapacious fishes have left their remains in these 

 rock, and probably more will be found with the progress of dis- 

 covery. 



In this group in Nebraska, the remains of sharks are quite abun- 

 dant. Many fine specimens of their teeth have been obtained in 

 the Inoceramus bed at Pleasant Hill in Saline County, from near 

 Seward, Milford, and in Dakota County. Some of these teeth 

 represent the pavement teeth kind (Cestraciont — Pycodus Mortoni), 

 and others the common modern shark family. 



Reptiles. — Manv reptilian forms from the west have been de- 

 scribed by Leidy, Marsh and Cope. The latter, from the Niobrara 

 Group of Kansas, alone, has described thirty-seven species of rep- 

 tiles. Many of these I have identified from the same group in 

 Nebraska, and as this group is continuous through these two States, 

 it is almost absolutely certain that they all, or their equivalents, 

 -warmed here during those times. What adds to this probability 

 is the certainty that there were deeper sees towards the northern 

 boundary of the Niobrara Group waters. u In the deep seas of 

 this era could have been seen an animal lying on the water, with a 

 body of elephantine size. Its neck was twenty-two feet long, 

 snake-like, and with an arrow-shaped head. One minute it would 

 run this long neck in the water, and then, raising it up, would peer 

 for victims over the deep. Its tail was also of serpent pattern, and 

 served to balance it behind, or propel it through the water, though 

 it also had two pairs of paddle-like limbs, resembling those of the 

 Plesiosaurus, from which it differed mainly in the arrangement of 

 the bones of the breast. This is the Elasttiosaurus platyurus, (Cope), 

 a carniverous sea reptile adapted to deep water. Its total length 

 was fifty feet. It was structured to swim below or on the surface, 

 and while lying still would explore the depth forty feet below with- 

 out changing the posture of its body. That it fed on fishes, is evi- 

 dent from the scales and teeth found in the posibon of its stomach." 



