NO. 1665. 



TWO SPECIES OF FOSSIL TURTLES— HAY. 



193 



from their original positions in the skeleton. The pygal is not 

 present. 



A few neural bones are present, 12-16. These show that there was 

 a sharp keel running along the middle of the carapace. The number 

 17 is placed at the side of an ossicle that had a position across the 

 suture between two of the neurals, as in other species of the genus. 



Several of the costal plates are present, but some are missing. 

 The}^ have the form usual in the genus, the distal half being very 

 narrow, 37-39, ^-^7, 53. 



The plastron is present, except the left epiplastron and probably 

 the right xiphiplastron, but the various bones have been slightly dis- 

 turbed. The front of the plastron was covered with other bones in 

 a way to hide it, and some of these had to be lifted temporarily. 



Fig. 1. TOXOCHELY.S STEiNOPORA. PLASTEON. X i- Ctlt, ENTOPLASTRON ; Cpi, KPIPLAS- 



TRON ; liyo, HYOPLASTRON ; hypo, hypoplasteon ; xiph, xiphiplastron. 



As accurately as possible, the plastron has been restored in fig. 1. 

 The epiplastra and the entoplastron have not, so far as known to the 

 writer, been hitherto observed. Each epiplastron is a narrow, curved 

 bone 33 mm. long, whose blunt anterior end joins its fellow. These 

 bones were not prolonged forward as they are in Chelydra and the 

 Cheloniidse. The entoplastron is a spear-shaped bone, close to 10 mm. 

 wide in front and narrowing posteriorly to a blunt point. 



The other bones of the plastron resemble closely those of the type 

 of the species." The bridges have a width of 38 mm., which is equally 

 divided between the hyoplastron and the liypoplastron. The xiphi- 



« Fossil Turtles of North America, fig. 220. 

 Proc. N. M. vol, xxxvi — 09 13 



