260 FOSSIL TURTLES OF NORTH AMERICA. 



According to Cope, the intergular scutes formed a single shield, which was large, pentag- 

 onal, with straight sides, and broader than long. This shield separated widely the gulars 

 from each other. The pectorals encroacht on the entoplastron; laterally they were narrow. 

 The abdomino-femoral sulcus crost the hypoplastra a little behind their middle. The median 

 longitudinal sulcus pursued an erratic course. 



This species evidently resembled closely Z. striatula. The distinguishing character most 

 obvious is the finer and conspicuously punctate sculpture. Cope states that the costal pro- 

 cesses that fit into the peripherals of Z. striatula are relatively twice as large as those of Z. 

 microglypha. 



In its sculpture this species resembles the species of Adocus. 



Genus HOMOROPHUS Cope. 



A remarkable, but insufficiently known genus of Dermatemydidae. Costal rib-heads 

 wanting or vestigial. Neurals, in the type and only known specimen, co-ossified with the cos- 

 tals. The superior face of each neural much wider than the inferior face. Vertebral scutes in 

 most places narrower than the neurals. 



Type: Homorophus insuetus Cope. 



Homorophus insuetus Cope 



Homorophus insuetus, COPE, Proc. Amer. Philos. Soc., XI, 1870, p. 552; Ibid., XII, 1871, p. 44; Vert. 

 Cret. Form. West, 1875, p. 263.- HAY, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 446. 



The type of this species appears to be lost. It was discovered in the uppermost bed of 

 Cretaceous greensand, at Pemberton, Burlington County, New Jersey. Cope does not state 

 what parts of the shell he had, but he describes some neural bones, the entoplastron, the 

 hyoplastron, the hypoplastron, and some costals. He had neither the epiplastra nor the 

 xiphiplastra. 



The hyoplastron and the hypoplastron together measured 200 mm. along the midline. 

 On comparing these parts of the plastron with the same parts in Baptemys it is concluded that 

 the plastron had a length of about 420 mm. 



The sutures bounding the neural bones appear to have been obscure. Cope says that one 

 of the neurals was 14 mm. thick, 60 mm. long, 28.5 mm. wide in front, and 91 mm. wide 

 behind. It is possible that there was here some error in observation or in statement. On the 

 visceral face the neurals were very narrow, but they expanded, so that a transverse section 

 resembled that of a broad wedge with truncated apex. The vertebral scutes had a remarkable 

 form. For the most part, they were narrower than the neural bones. One is described as 

 having the front coffin-shaped, the lateral margins concave, and the posterior end expanded, 

 so that the scute was fiddle-shaped. The anterior vertebral is stated to have been 60 mm. 

 long and 35 mm. wide anteriorly. The posterior costal scutes are described as meeting 

 in the midline behind. 



The thickness of the hyoplastron was 15 mm. The free border of the hypoplastron was 

 thinned to an edge. 



Genus ALAMOSEMYS nov. 



Differs from Adocus, so far as known, in having the marginal scutes wholly excluded from 

 the costal bones. 



Type: Alamosemys substricta Hay. 



The generic name is derived from the name of the stream where the type was found. 



Alamosemys substricta sp. nov. 



Plate 39, figs, i, 2; text-figs. 323, 324. 



The specimen which serves as the type of this species was collected in the Torrejon 

 deposits of New Mexico, near the head of Alamosa Creek, in 1896, by Dr. J. L. Wortman 

 and Mr. W. Granger. It bears the catalog number 1204, in the American Museum. 



