330 



G. R. Wieland — On Marine Turtles. 



monly present in Cretaceous turtles, and may now be consid- 

 ered to have been definitely traced to its origin in at least one 



Figure 3. — Lateral view of the 

 Carapace of Toxochelys Bauri Wie- 

 land, x )4 nearly. Drawn from the 

 type, s, s, s, the three Epi-nenral 

 spines supported respectively by the 

 3d and 4th, the 5th and 6th neurals, 

 and the 8th nenral and the post- 

 neural elements ; /, the post-nuchal 

 foramina. 



* Kansas Univ. Geol. Survey, vol. iv, p 



Epi-neural Spines —The ser- 

 ies of epi-nenral spines taken in 

 conjunction with the strongly 

 carinate neurals, and the keeled 

 marginals, give to the present 

 fossil carapace a most ornate 

 form. See figures 1 and 3. 



The earliest suggestion of the 

 possible presence of epi-neural 

 elements in the Testudinata was 

 made by the writer in his orig- 

 inal description of the Fort 

 Pierre Cretaceous turtle Arehe- 

 lon given in this Journal for 

 Dec, 1896. It appears on page 

 400 of that number as follows : 

 "One of the chief features of 

 the carapace is the arching into 

 a heavy dorsal ridge, beginning 

 just back of the region of the 

 first dorsal vertebra, and from 

 thence continuous, except in the 

 sacral region. It marks the 

 position of the neural spines 

 and is very distinctly grooved 

 from anteriorly to the region of 

 the eighth dorsal vertebra. Im- 

 mediately over the neural spines 

 this groove inclines to widen 

 and send out asteriations. In 

 life these grooves were no donbt 

 filled with horny material, and 

 the animal may have home a 

 dorsal row of spines" 



Two years later the spines of 

 Toxochelys were first observed 

 by Case,* and have been since 

 more fully described and com • 

 mented on by Hay, who would 

 see in them the remnants of a 

 former dermal series, probably 

 once common to all turtles, and 

 to explain the homol- 



382 (1898). 



o;oillp; far 



