146 THE WASATCH AND T^UinGKK FADNiB. 



They are composed of the produced edges of two coossified costal bones, 

 united with the ascending buttresses of the plastron. 



The affinities appear to be to Adocus on the one side and Hi/dra-npididie 

 on the other, perhaps as descendant of the former and ancestor of the latter. 

 It also possesses traces of the other relationships of Adocus, i e., to Dernia- 

 temys, and more remotely to Chehjdra. 



Baena hebraica Cope. 



Baicna kehraica, Proceed. Amer. Philos. Soc, 1872, p. 463 (published July 29). Annual Report U. S. GeoL 



Sarv. Terrs., 1872, p. 621. 



Plate XIX, figs. 1-2. 



General form depressed and discoid, as wide as long. Bridge wider 

 than long, but the length equal to the width of the bases of the sternal 

 lobes. Anterior lobe longer than wide at the base, and narrowed at the 

 extremity. The inguinal and axillary septa are very prominent. The edge 

 of the carapace from the front to the inguinal region, is without emargina- 

 tion. All the osseous elements are coossitied. 



The scuta are well distinguished. Tlie nuchal is very small and wider 

 than long; the first marginal is shorter but more prominent. The second 

 and third are larger but narrow; the fourth and fifth are wider, but the 

 sixth widens by an inward projection of its border so as to meet the inter- 

 costal suture between the second and third costal scuta. From this one to 

 the ninth (as far as presei'ved) the inner margins are produced so far as to 

 make the scuta nearly twice as wide as long when viewed from above. The 

 first costal is small; its posterior border is curved. The first vertebral is 

 pyriform, truncate in front. It is (perhaps abnormally) divided by a trans- 

 verse suture into a quadrate anterior and cordate transverse posterior por- 

 tion. The other vertebrals are somewhat longer than broad, and are sepa- 

 rated by sutures convex anteriorly. 



The intermarginal scuta are all wider than long; their number is nor- 

 mally four, but a narrow one is intercalated beliind the inguinal on one 

 side. The longitudinal sutui-e of the scutes of the plastron is exceedingly 

 tortuous, winding between points more than an imli apart. The gulars 

 and intergulars ai'e transverse and bounded bv transverse sutures. They 



