PLEUROSTKRNID^:. 



55 



been crowded out of contact with each other. The humerals measured 47 mm. at the midline; 

 the pectorals, 63 mm.; the abdominals, 5+ mm.; the femorals, about 78 mm. There were 

 doubtless inframarginals on the bridges, but the sulci are obscure. 



Since the preceding description was written a second specimen has been made available 

 for study. This was collected bv Mr. Barnum Brown, in 1904, in the Crow Reservation, 

 Montana, at a point about 50 miles southeast from Billings and about 25 miles east of Pryor. 

 The catalog number ot the specimen in the American Museum is 6071. It furnishes more of 

 the shell than does the tvpe, but unfortunately the plastron is fractured and faulted obliquely 

 to its length and the carapace is fractured and faulted in several directions. 



The carapace was about 325 mm. long and the width is close to the same. The anterior 

 border is preserved on each side to behind the axillary notches; it is obtuse and about 10 mm. 

 thick. The surface presents the same kind of sculpture as the plastron, consisting of low wind- 

 ing ridges. The sulci are rather obscure, but the vertebral scutes were broad, as in the type, 

 while the right third costal is seen to have been only 70 mm. high. 



The length ot the plastron appears to have been close to 295 mm. The bridge is 125 mm. 

 wide. From the line joining the free borders of the anterior and posterior lobes of the plastron 

 the bridge rose to the free border of the carapace, a distance of about no mm. The hinder 

 lobe has a width of 125 mm. and a width of 1 10 mm. at its base. At theendsof thefemoro-anal 

 sulci the width is 83 mm. The hinder border confirms the accuracy of fig. 32. On the bridges 

 are some indications of inframarginal scutes, too obscure to be traced. 



mg.b 



Figs, jj and ^4. Glyptops depressus. Specimen in U. S. N. M. 



33. Carapace of type. Xj. 



34. Portion of plastron of type. X. ax.h, axillary buttress; ent, entroplastron; epi, 



hyoplastron; hypo, hypoplastron; ing. b, inguinal buttress; mes, mesoplastron. 



epiplastron; hyo, 



Glyptops depressus sp. nov. 

 Text-figs. 33, 34. 



The type of this species belongs to the United States National Museum. It appears to 

 have been secured by one of Professor O. C. Marsh's collectors in 1889, inasmuch as it bears 

 his packing number "1998. Box 3." W ith the specimen comes a statement by Mr. Whitman 

 Cross, of the United States Geological Survey as follows: 



"No. 2 Box B. '89,' (Cannon's designation). An isolated fragment. (I think this fossil is 

 from the Denver beds, from the nature of the sandstones between the shells and the apparently 

 zeolitic material in cells of the bone.)" 



Professor Marsh has recorded Compsemys phcatula from the Denver beds, but whether on 

 the evidence of this specimen can not be determined. The probabilities that the same species 

 is found from the top of the Jurassic to the top of the Cretaceous are remote. 

 1^3 The specimen presents considerable portions of the carapace and of the plastron. The 



