284 MEMOIRS OF THE CARNEGIE MUSEUM 
ing of the specimens of the Niobrara chalk, no wide differences in proportion are 
evident on comparison with the much larger turtles of the genus Archelon from the 
Fort Pierre Cretaceous. ‘The lack of codéssification of the mandibular rami and 
especially the very low radial crest of the latter form will, however, serve to dis- 
tinguish it from the fossil before us. But of far greater interest than any question 
of generic values that may arise is the fact that the bones of the hand are, with 
the sole exception of the radiale, indisputably in place, the most striking fea- 
ture being the immense ulnare, and the strong contact of the intermedium with 
the first carpale. With these remarks we may pass on, basing our main de- 
scriptions on the earlier secured and in some respects better specimen with its several 
elements freed from their matrix. 
Specimen No. 1420 (Carnegie Musewm Catalogue of Vertebrate Fossils). — The 
present specimen of Protostega gigas is more nearly complete than any other as 
yet discovered. As originally imbedded in its matrix of chalk, nearly every ele- 
ment was present in an exactly or approximately natural position, and recovered 
as follows: 
1. Portions of the skull, with the crushed lower jaw and two large and well 
preserved paired hyoids. 
2. The Ist, 4th, 5th, 6th, 7th and 8th cervical, the dorsal, sacral, and eight anterior 
caudal vertebrae. 
3. The nearly complete series of ribs, including the anterior pair of sacral ribs, 
also the neurals, and various marginals. 
4. The left shoulder-girdle and proximal half of the humerus, with the right 
shoulder-girdle and complete front flipper in place, except the ungual phalanx of 
the fourth and the second phalanx of the fifth digit. 
5. The pelvic girdle and hind limbs complete and in place, less only the fibu- 
lare (if ossified), the ungual phalanges of the right, fourth, and fifth digits and of 
the left fifth digit. 
6. A nearly complete though very much crushed plastron. 
Unfortunately the collector of this surprisingly complete fossil, in an attempt to 
remove and separate the bones from their matrix of chalk, mis-marked some of them, 
and also made it virtually impossible to either replace more than a very few of the 
marginals, or to determine the outlines of any of the plastral elements with exact- 
ness. Hence it is not worth while, in view of the marked crushing undergone, to 
give figures of any of these parts now, although they will aid in the restoration, 
As will be evident to any student of the fossil vertebrates the removal of the fossil 
from its matrix in the absence of the necessary knowledge, training, and equipment, 
