PROTOSTEGID&. 207 
being 465 mm. At the hinder end of the symphysis its depth is 110 mm., and the width of 
the jaw, 155mm. On the under surface the symphysial end of the jaw turns strongly upward 
but the upper surface rises little. Wieland found the splenial to be present. - , 
Wieland has described 5 cervical vertebra (fig. 266, cer. v) which belonged to the type 
specimen (Amer. Jour. Sci., 11, p. 401; XIV, p. 102). These centra indicate a neck of great 
strength. The centrum of one, regarded as the third or the fourth, is proccelous, 95 mm. long 
and 140 mm. wide. Dorsal, sacral, and caudal vertebra also are described by the same auithes 
The shoulder-girdle of the type specimen was described by Wieland (Amer. Jour. Sci. 
i, p. 404). The scapula (fig. 266, scap) is a stout and heavy bone, resembling that of Peo 
tostega. The length of the body of this bone, from the upper end to the glenoid fossa, is 
450mm. The coracoid (fig. 266, cor) is elongated and slender, as in Protostega. The length is 
650 mm., the width of the distal end, 127 mm. : 
A sit 
Fic. 267.—Archelon tschyros. Limb bones. X 1. 
fem’, left femur, dorsal surface; fem’’, left femur, tibial border; fem’, proximal end of left femur, fibular border ; 
fib, fibula; hum, left humerus; rad, ulna; tb, tibia; u/, radius. The bones marked rad and u/ should 
exchange places, be placed with the other ends up, and exchange explanatory letters. 
The humerus (figs. 266, 267, hum) is an enormous bone, the length from the head being 
580 mm.; the total length, 650 mm. The width of the distal end is 340 mm. This bone differs 
from that of Protostega in having a relatively smaller head and the radial process much reduced. 
Wieland describes also the radius, the ulna, and some phalangeal bones. The figures by 
Wieland are here reproduced. In the figure of the fore limb the upper ends of the ulna and 
the radius have mistakenly been represented as the lower. When the ends are reversed they 
will have the positions that they have in Wieland’s figure of the anterior flipper of Protostega 
gigas. The bones must also exchange places and legends. 
The pelvis of the type specimen is described and figured in the journal so often quoted 
(vol. 1x, p. 247). The figure is here reproduced (fig. 268). This pelvis is of astonishing size, 
the length and the width being each nearly half the length of the carapace. In general, its 
