336 



G. R. Wieland — On Marine Turtles. 



Plastron. — Of the same Chelydroid form seen in Osteopygis 

 and Lytoloma. 



Figure 7. — Toxochelys Bauri (type). Bestoration of the plastron, x \. — 

 The stippled surface shows the portions of the hyoplastron (h) and the hypo- 

 plastron (hp) actually recovered. — (The epiplastron and entoplastron is only 

 known in T. latiremis, cf. figure 8, and the xiphiplastron in T. stenoporus.) 



Specific Relationships. 



The specific identity of the Toxochelys described in the 

 foregoing pages with any of the known species of the genus 

 cannot be affirmed, as appears from the following analysis. — 

 Five species have been assigned to the Niobraran genus Toxo- 

 chelys as first established by Cope in 1873, namely : T. latire- 

 mis, the generic type ; T. serrifer, Cope, 1875 ; T. brachy- 

 rhinus. Case, 1898 ; and T. procax and T. stenoporus, as pro- 

 posed in a recent revision of the genus by Hay (8). 



With T. latiremis as close a comparison as desirable is not 

 yet afforded, since but few of the elements of the carapace and 

 plastron of this form are known. It appears, however, that 

 the nuchal was of markedly different proportions from those 



