G28 GE0L0C4ICAL SURVEY OF THE TEREITQRIES. 



3l€asurements. 

 No. 1. 



M. 



Width i)laRtrou at axilla 0. OrO 



Leiijitli plastron from axilla, (approximate) 05 



Tliickiicsis hyosternal at mcsostenial 009 



Thickness hyosternal at hyposterual 00(55 



Width niesosternal 0:57 



Length niesosternal 02G 



Thickness of a vertebral OOG 



Thickness of xijjhisternal, (normal) 004 



Thickness of xiphisternal at pubis 007 



No. 2. 



Thickness co.stal at hump 0075 



Width of costal 0175 



No. 3. 



Width of posterior marginal ■■ 027 



Length of posterior marginal 019 



The iiiesosterii«a], tliougli found with No. 1, does not fit it exactly and 

 does not belong to it. 



From Gieeu iUvcr formation near Evanston, Wyoming. 



• 



Emys euthnetus, Cope, sp. nov. 



Eepreseuted by numerous portions of several specimens. These per- 

 tained to a species of about the size of the salt-water terrapin, Mala- 

 coclemmys iw^KS^r/s. There is no dorsal keel, and the scutal sutures, 

 though distinct, are not very much impressed, nor the interspaces swol- 

 len. The lip of the plastron is narrow, thick, and not notched; the 

 sutures of the gular scales do not extend on to the mesosternum. The 

 margins of the lobes of the plastron are a little thickened and the su- 

 tures of tlie bones coarse, and at the hyposiphisternal junction, &c., 

 with gompliosis. (It is fine and close at this point in U. testudineus.) 



The costal sutures for the bridge are projecting and curved in one 

 position ; in the other straighter, and very near the margin of the cos- 

 tal bone. Surfaces smooth. 



Abundant in the red beds which lie between those of the Green Eiver 

 and Bridger epochs at Black Biittes, Wyoming. 



Emys megaulax. Cope, sp. nov. 



Eepreseuted by remains of two specimens. They pertained to a spe- 

 cies of about the size of that last described. The marked peculiarity 

 consists in the broad and abruptly sunken sutures which separate the 

 dermal scuta of the carapace. This is visible on vertebral, costal, and 

 marginal bones, where the area) between the sutures are abrui)tly sep- 

 arated. The sutures partially interrupt the dorsal carina. This is 

 wide and low. The sculpture is otherwise smooth. The scutal sutures 

 are not so impressed on the plastron, and those of the gular scutes ex- 

 tend on the mesosterual bone. 



Mcasiirements. 



M. 



Length of a marginal OIG 



Width of a marginal ()23 



Width of a vertebral 018 



Length of a vertebral t)17 



