PLEUROSTERNIDZ. 53 
The first costal (plate 7, fig. 1; text-fg. 28) has a length, from its union with the neural 
to the pointed distal end, of 103 mm. and a width, fore and aft, of 50 mm. The thickness of 
the costal at the posterior border is about 5 mm. ‘The anterior half of the bone is thickened 
to as much as 18 mm. to forma shoulder for the reception of the axillary buttress of the plastron. 
The latter must have been considerably more strongly developt than in Glyptops plicatulus. 
The head of the rib is stout. The first rib lies in front of and against the rib of the first costal 
plate. The first peripheral lacks its anterior half so that its antero-posterior extent can not be 
accurately determined. However, the missing portion is partly supplied by No. 1939. The 
anterior, or free, border is obtuse. At one end is the sutural surface for union with the nuchal 
bone. It appears quite unlikely that there was any considerable excavation in the front of the 
carapace for the neck of the animal. The first peripheral of No. 1930 was 30 mm. wide, 
parallel with the edge of the shell. The second peripheral has a fore-and-aft extent of 40 mm. 
and the width along the free border is the same. This border also is obtuse (fg. 29) and at a 
short distance from the edge the thickness is about 8 mm. It resembles very closely the 
corresponding one in G. plicatulus. 
The posterior peripheral, probably the tenth of the right side, numbered 1939, 1s 39 mm. 
wide from the free border to the union with the costal, and 35 mm. along the free border. 
Its thickness, where it joined the costal, is 10 mm., and it has come down to an acute free 
edge (fg. 30). Its form is therefore that of a thin wedge. 
The fragment of costal numbered 1930 (plate 7, fig. 2; text-fig. 31) shows neither the 
length nor the breadth. The piece is 35 mm. wide and has an epidermal sulcus running 
parallel with the sutural border and 27 mm. distant from it. The costal was therefore of 
considerable total width. Its thickness is only 5 mm. “The true rib does not appear on the 
lower surface, as it does in G. plicatulus. 
The sulci of this species are narrow and shallow, but quite distinct. Apparently the 
epidermal scutes resembled those of G. plrcatulus, altho neither the vertebrals nor the marginals 
were so broad as in the latter species. 
The sculpture of the surface is quite different from that of G. plicatulus. In the latter it 
has a more granular appearance and is produced by distinct raised dots and by short ridges 
formed of coalesct dots. In G. celatus the dots are larger, the ridges also broader, longer, and 
smoother. The spaces between the elevations are as wide as the latter. In the centers of the 
bony surfaces the ridges are irregular in length and direction, and often vermiculate. Border- 
ing the sutural edge is a broad Bandi in mice the ridges and grooves run at right angles with 
the suture. On aye costals this band may be as Tahch as 13 mm. wide. 
Glyptops? belviderensis (Cragin). 
Plate 7, figs. 4, 5. 
Plesiochelys belviderensis, CRAGIN, Colorado Coll. Studies, v, 1894, p- 71, pl. 1, figs. 1-8.—Hay, 
Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 439- 
The present writer has not seen the type specimens of this species. They belong to Colo- 
rado College, Colorado Springs, Colorado. ‘They consist of two first costals, fragments of other 
costals, a eal bone and a dorsal vertebral centrum. These bones were feuinid’d in the Kiowa 
shales, a portion of the Comanche series and near the top of the Lower Cretaceous. The 
locality is near Belvidere, Kiowa County, Kansas. 
Dr. Cragin referred these bones to the genus Plesiochelys, but there appears to be no special 
reason for this assignment. The species of this genus, so far as certainly known, belong to the 
Jurassic, Kimeridge, and Wealden of Europe. “i he sculpture of the costals of Cragin’s species 
suggests Glyptops Valahas and accordingly the species is referred with doubt to Glyptops. Two 
of Cragin’s figures are here reproduced. Fig. 5, plate 7, represents a neural seen from the 
under ede It is relatively considerably ioader than theneuralsof Plestochel ys (Zittel’s Hand- 
buch Palzontologie, p. 545, fig. 502; Lydekker’s Cat. Foss. Rept., pt. 11, fg. 44). The front 
costals figured by Cragin are narrow, the width being 38 mm., the length $2 mm. The longest 
costal was III mm. long. The upper surface of fhe. shell is said to Re ornamented with deli- 
cate vermicular grooving and pitting. Fig. 4, plate 7, is intended to represent this sculpture 
of the costals. 
