WIELAND : THE OSTEOLOGY OF PROTOSTEGA 285 
was ill advised. Such work is difficult enough in the best equipped labora- 
tories. However none of the bones of the limbs are broken, and Mr. Sternberg 
redeemed himself by discovering and securing in such excellent condition specimen 
No. 1421, as just related. The position of the following parts is independently 
determinable : 
1. The fourth to the eighth cervical, the dorsal and sacral centra, with the 
proximal caudal vertebrae and most of the ribs as shown in part in Fig. 2. 
2. The shoulder-girdles and elements of the fore-arm ; in particular (as can be 
determined by actual close articulation, or by such intervening matrix as the col- 
lector permitted in much too small part to remain), the intermedium, first carpale, 
metacarpale and its phalanges, and also carpalia 3-5. 
3. The pelvic girdle and elements of the hind flipper, in particular the inter- 
medio-centrale and tarsalia 1-3, and 4 and 5 (fused), as well as several metatarsals 
and phalanges. 
It should be stated here that it is claimed that, as figured, no element of either 
flipper is actually misplaced, although the extent of the crushing undergone makes 
it quite possible that in one or two instances dorsal surfaces have been mistaken 
for ventral ones, or vice versa, and that the ends of several phalanges may have 
been reversed. Withal it is deemed important to be thus explicit in giving the 
manner in which the accompanying text-figures and photographs have been 
obtained, before taking up more detailed description. (Because of the compression 
undergone it was not thought needful to figure either the lower jaw, cervicals, or 
caudals. The dorsal view of the carapace can better be given after the restoration 
now being made. 
I. Tae Carapace. (Fig. 2. 
fo} 
With the exception of the T-shaped nuchal and the marginals with dactylate 
interior borders so peculiar to the Protosteginee in distinction from all other known 
marine turtles, the main features of the carapace are very well represented in Fig. 
2. The very thin, almost paper-like series of neuralia is present, though much 
erushed down on the underlying neural arches. The ribs are free through at least 
the distal two-thirds of their length. The first pair is comparatively slender, it not 
being clear as to whether, or not, their distal extremities rested on the lateral alee- 
like expansions of the nuchal. The shield contour is, instead of elongate as once 
supposed, relatively broader than in either Thalassochelys or Chelone, the ratio of the 
length of the dorso-sacral series to the breadth of the carapace being as three to four. 
