BOTHREMYDID. 109 
The borders of the fourth and fifth neurals are 8 mm. thick. On the under side of each 
is attacht the neural arch of the corresponding vertebra. The eighth neural was not developt 
and the costals of the seventh and eighth pairs met at the midline. The ninth and tenth dorsal 
vertebra and the first sacral appear to have had their arches articulated with the inferior 
surface of the seventh and eighth costals at their junction. The accompanying table gives the 
dimensions of the three posterior neurals. 
The nuchal bone is urn-shaped, go mm. long, 43 mm. wide in front, 86 mm. across the 
widest part, and 10mm. thick. Its free border is acute. The first peripheral measures 58 mm. 
along its free border; the second, 53 mm. The first appears to 
have been about 60 mm. high, measured at the suture with the 
second. The free border of these two peripherals is subacute. 
The greatest thickness of the second, at the distal end, is 12 mm. 
66 67 On the right side most of the peripherals are wanting from the 
E x * second to the eighth (exclusive of both); all are missing behind the 
: second on the left side, except one, probably the sixth. The upper 
and lower faces of this sixth meet at the acute free border at an 
angle of about 45°. This border is 45 mm. long and from this the bone rises 56 mm. to the 
costals. In the restoration (fig. 101), this bone has been omitted from its supposed place. 
The lower face of the bone, that proceeding to the plastron, is mostly missing. 
Neural. Length. Height. 
Fic. 101.—T aphrosphys longinuchus. Carapace of the type. 4. The stippled areas 
represent the known bones. 
All of the peripherals have acute free borders. Of the eighth, that portion to which the 
inguinal buttress was attacht is broken away. From the free border each of these bones 
thickens on the under side to half its height, then becomes gradually thinner. 
The suprapygal is triangular, 62 mm. long and 60 mm. wide posteriorly. Evidently it 
articulated on each side with the eleventh peripheral and medially with the pygal. 
