l8 KANSAS UNIVERSITV QUARTERLY. 



I. — CJtchuiioidra. A parieto-squamosal arch: articular faces between 

 sixth and seventh cervical vertebras plane, nuchal with a distinct 

 process on the lower side for the articulation with the neuroid of the 

 eighth cervical: no lateral processes of nuchal. One biconvex cer- 

 vical vertebra. 



I. — DcsDiatoclielyidcc. Palatine foramina present, a descending pro- 

 cess of the parietals: free nasals present; limbs paddle-shaped. 

 Desmatochelys . 



2. — Cheloniidce. Palatine foramina not present; a descending pro- 

 cess of the parietals; no free nasals: limbs paddle-shaped; claws 

 one or two. Chelone, etc. 



3. — DeniiocJielyidu'. No free nasals, no palatine foramina; no 

 descending process of the parietals; no claws; limbs paddle-shaped. 

 Bony carapace dissolved into numerous mosaic-like pieces. Deri/io- 

 r/ie/ys. 



Of course a more perfect knowledge of Dcsuiatochclys may ne- 

 cessitate a yet further revision of the different group-characters. 



Lawrence, May 5, '94. 



