288 MEMOIRS OF THE CARNEGIE MUSEUM 
The carpal and finger organization of Protostega has been hitherto wholly un- 
known, and, in fact, the only fossil marine turtle from America in which these 
parts have been described is Toxochelys.'’’ In discussing the carpal organization it is 
of foremost importance to recall that the itermedium, carpale 1, and metacarpale 1, 
as well as carpalia 3-5, are still naturally articulated as in life, and in all particulars 
agree precisely with these same elements in specimen No. 1421. Nor is there any 
Fig. 4. Protostega gigas. Right shoulder girdle and flipper. 1. Niobrara Cretaceous. SS, scapular ; PC, pro- 
coraco-scapular ; C, coracoid ; H, humerus; R, radius; U, ulna; r, position of the radiale ; 7, intermedium ; w, ulnare ; 
c, centrale ; 1-5, first to fifth carpalia ; p, pisiform ; m, metacarpal 1; p, phalanx 1; I.—V., first to fifth fingers and un- 
gual phalanges. The view is dorsal with the procoraco-scapular rotated into the plane of the paper. 
further doubt concerning the identification of the other elements and agreement im 
toto with that specimen. As so clearly shown in the figures and photographs, the 
triangular-shaped centrale articulates strongly with carpale 1. I have supposed 
this was not the condition in Archelon,” but must have been in error. No radiale 
was recovered. Bearing in mind that the several carpal elements are somewhat 
crushed, no further detailed description of them appears necessary, except that it 
should be remarked that the ulnare is of sub-hexagonal outline and relatively very 
large, being of the general form seen in Thalassochelys, and especially Colpochelys, 
rather than Dermochelys. The ulnare of Archelon is of nearly the same relative size, 
12 Wieland, ‘‘ Notes on the Cretaceous Turtles Toxochelys and Archelon, with a classification of the Marine Testudi- 
nata,’”’ Am. Jour. Sci., Vol. X1V., August, 1902. 
Loc. cit., Wieland, ‘‘ Notes on Toxochelys and Archelon,’’ etc. 
