m- umatkmyimd.*:. 



267 



From H. crassa the present species differs in having the supposed seventh peripheral 

 strongly sutured to the contiguous costal bone, in having no lateral carina, and in having the 



longitudinal sulcus at the middle of the 

 height, instead of near the costal border. 



In the inner face of the bone are excava- 

 tions for the reception of digitations from the 

 plastron. One of these digitations remains in 

 position, and shows that it extended backward 

 a short distance into the eighth peripheral. The 

 border which articulated with the costals is 7 

 mm. thick. In the sutural edge is a deep pit, 10 

 mm. in diameter, which received the extremity 

 of the rib of the contiguous costal plate. 



Fig. 328 shows the type peripheral as 



seen from the outside. The drawing on the 



hinder end of the bone; the one on the left, the anterior end. 



Fig. 528. Hoplochclys paludosa. Supposed left 

 seventh peripheral forming type. X. A.M.N.H. 



a, bone seen from side; b, anterior end; r, posterior end; d, an 

 adhering fragment of the plastron. 



right presents a view 



iA tin 



Genus KALLISTIRA nov. 



Carapace thick and solid; provided with a median and two lateral carina;. Plastron 

 unknown, except that its inguinal buttresses were extensively developt and ascended a con- 

 siderable distance against the inner surface of the fifth and sixth costals. 



Tvpe: Dermatemys costilatus Cope. 



Kallistira costilata (Cope). 



Figs 329-334. 



Dermatemys? costilatus, Cope, Syst. Catalogue Vert. Eocene, N. Mex., 1875, p. 36. 



Dermatcmxs costilatus, Cope, Report on Geol. N. Mex., 1874 (1875), p. 96; Wheeler's Surv. 100 Merid., 



iv, pt. ii, p. 52, plate xxiv, figs. 17-31. 

 Baptemxs costilatus, Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 445. 



The types of the present species belong to the U. S. National Museum and bear the number 

 1 152. Not all the fragments that Cope figured are present. Those missing are the originals 

 of Cope's figs. 17, 20, 23, 24, 26, and 31. Cope states that he had fragments representing 6 

 individuals, and that parts of 4 were figured. There appears to be no reason for doubting 

 that all of these individuals belonged to the same species. Figures of some portions of these 

 types are here presented. The species was found in the Wasatch beds of New Mexico. 



The species is characterized By its thick and heavy shell and the presence of at least 3 

 carinae on the carapace, one running along the midline and one on each side of it. 



The fragment which furnisht Professor Cope's figs. 27 and 28 belongs to the upper end of 

 a costal, probably either the second or the fourth. Cope's fig. 27 (fig. 329) is inverted on 

 his plate. The width of the costal is 20 mm. It is crost by a low keel whose breadth is almost 

 9 mm., but whose elevation is scarcely a millimeter; the thickness of the costal above the carina 

 being 6 mm., that thru the carina, 7 mm. At the distal end of the fragment the thickness 

 is 5 mm. This piece of costal presents a part of the sulcus bounding a vertebral scute laterally 

 and the sulcus running down the costal. These are extremely narrow and shallow. The 

 longitudinal sulcus is at a maximum distance of 10 mm. from the proximal border of the costal 

 and above the lateral carina. The vertebral scutes appear to have had a width of about 

 42 mm. The proximal end of the costal is rounded, showing that the lateral borders of the 

 adjacent neural were concave. Another costal, the one furnishing Cope's figs. 19 and 19a, 

 belonged to a smaller individual. The carina is still less conspicuous than in the case of the 

 one just described. The original of Cope's fig. 21 (fig. 330) has the carina more sharply 

 defined and with a width of 5 mm. It is probable that, as suspected by Cope, the carinae 

 were developt on the rear of the animal and disappeared anteriorly. 



Fig. 331 represents the original from which Cope obtained his fig. 30. It is a portion of the 

 distal half of a costal, in all probability the fifth of the right side. The extreme end of the bone 



