45 



iu the axillary region but elsewhere the shell is thin. The anterior border is evenly- 

 rounded. 



The front end of the plastron (figs. 10, B and 0) is rather broad in proportion to the 

 length of its component parts of which the epiplastrals, the entoplastral and small por- 

 tions of the hyoplastrals are preserved. The entoplastral, seen from below is diamond 

 shaped, a little broader than long, and placed far forward on account of the shortness of 

 the suture between the epiplastrals in front. Seen from above, or within, the entoplastral 

 is much longer than broad, its breadth being reduced and its posterior half prolonged 

 backward. Similar extensions of the posterior border also occur in the upper surface of 

 the epiplastrals. Sulci, as indicated in the figure, define the boundaries of thegular and 

 intergular shields. 



Other fragments, in the collection, may help to further elucidate the structure of the 

 shell of this species. 



Belly Eiver series ; below the mouth of Berry creek. Red Deer river, 1901. 



Measure'inents. 



M. 



Extreme length of specimen, on median line • 186 



Estimated length of carapace • 290 



Length of 1st neural • 033 



Breadth of same • 027 



Length of 2nd neural • 030 



3rd " ■ -037 



" 4th " 032 



5th " „ -031 



Length of 3rd vertebral shield . , ■ 065 



Extreme breadth of same • 075 



Breadth of entoplastral, lower surface • 027 



Length of same • 022 



Thickness near front margin of carapace • 007 



" " plastron ■ 0065 



Thickness of 2nd costal at proximal end -005 



'■ " distal end -004 



Maximum thickness in axillary region • 026 



Belly River series, Red Deer river, 1901. 



RHYNCHOCEPHALIA. 



CHAMPSOSAURID^. 



Champsosaurtjs, Cope. 



Champsosaxjrxjs annectens, Cope. 



Vertebrre, Leidy. 1860. Trans. Amer. Philos. Soc. Extinct Vertebrata from the Judith river 

 Great Lignite formations of Nebraska, p. 147, pi. 9, figs. 56-61. 



Champsosaurus annectens, Cope. 1876. Proc. Acad. Nat. Sci. Philadel., p. 351. 



and 



