TESTUUINIIX*:. 



407 



belongs to this specimen it must be the eleventh, and the height of the peripherals was rapidly 

 reduced from the ninth, inasmuch as the supposed eleventh is only 64 mm. high. Its thickness 

 is 26 mm. The upper surface is nearly plane, while the inferior is convex in section at right 

 angle with the free border. Fig. 521 is a section taken near the posterior sutural border. Cope's 

 measurements indicate that he had one other hinder peripheral, but this is not now present. 

 Curiously enough, his dimensions apply exactly to the first right peripheral. 



The sulci are narrow and sharply imprest. The nuchal scute is 40 mm. long and only 9 

 mm. wide. On the lower side of the bone this scute has a posterior width of 25 mm. The 

 sulcus between the first and second marginals is 62 mm. long. The anterior width of the first 

 vertebral has been 58 mm. 



Professor Cope figured the left epiplastron, as seen from below; but he erroneously stated 

 that the view is from above. A figure is here presented of the bone as seen from above (fig. 

 522). The anterior lip projects abruptly from the general outline of the anterior lobe for a 

 distance of 35 mm. The anterior border of the lip is truncate, with the angle between it and 

 the lateral border clipt off. The whole free edge of the epiplastron is acute, except near 

 the midline, where it is slightly rounded. From the free edge of the lip the bone thickens 



525- 



FIGS. 523-525. TestuJo ligonia. Parts of plastron of type. X 2- 



523. Fragment of left hypoplastron, lower surface, a, suture with seventh peripheral; be, suture with siphiplastron; 



bd, suture with right hypoplastron. 



524. Section across left hypoplastron just in front of union with xiphiplastron. a, outer border; b, border at midline. 



525. Fragment of hyoplastron. Shows suture, cd, for union with entoplastron ; pec, pectoral scute. 



backward until it attains a thickness of 32 mm.; then suddenly drops off to 17 mm. The 

 portion of the epiplastron in front of the gulo-humeral sulcus projects nearly horizontally for- 

 ward, while the portion behind it ascends to meet it. On the lower side there is a decided 

 angle between the two portions. The sulcus runs forward in this angle. 



The fragment of hypoplastron (fig. 523) extends from the inguinal notch to the longitudinal ' 

 median suture and backward to the suture with the xiphiplastron. The base of the hinder 

 lobe is shown to have been 188 mm. wide. From the buttress a rounded ridge (fig. 524) 

 descended which past backward on the summit of a wall surmounting the border of the 

 lobe. The outer face of the wall is convex and 30 mm. high. From the summit the inner face 

 slopes gradually to the midline. The lower surface of this bone displays faint grooves on the 

 area of the femoral scute. 



The sulci of the plastron, like those of the carapace, are narrow and sharply imprest. 

 The gular scutes encroacht on the epiplastra. The humero-pectoral sulcus (fig. 525) crost the 

 midline about 8 mm. behind the entoplastron. The pectorals are 18 mm. wide at the midline. 



Under the species T. quadrata will be found mention of characters which distinguish it 

 from the present species. 



Tesrudo amphithorax Cope. 



Figs. 526-531. 



TestuJo amphithorax, COPE, Palaeont. Bull. No. 15, 1873, p. 6; Synop. New Vert. Tert. Colorado, 1873, 

 p. 19; Ann. Rep. Gaol, and Geog. Surv. Terrs., 1873 (1874), p. 511; Vert. Tert. Form. West., 1884, 

 p. 767, plate Ixi, fig. 4. HAY, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 451. 



Of this species Cope possest portions of 2 individuals which display the anterior lobe of 

 the plastron, and another which lackt this lobe. These specimens are now in the American 

 Museum of Natural History. The portions of the plastron which Cope figured are included 



