282 MEMOIRS OF THE CARNEGIE MUSEUM 
one very important specimen, a large Protostega, represented by a quite complete 
cranium and lower jaw, accompanied by a humerus, radius, ulna, wrist, and palmar 
bones — all in place on the same slab. The acquisition of this specimen has been 
as timely as fortunate; for it has removed all doubt as to the carpal and tarsal 
organization of Protostega, and made possible the avoidance of errors in the descrip- 
tion of the completer specimen, most of the elements of which had been dissociated 
from their matrix, and the position of some of them rendered doubtful through the 
mistaken zeal of their collector. It will hence greatly simplify our description of 
the limb organization of Protostega as based on the free elements of the original and 
completer specimen, No. 1420, Carnegie Museum Catalogue of Vertebrate Fossils, if 
the more recently acquired and less complete Protostega with its parts In approxi- 
mately natural position, be considered first. ; 
Protostega gigas Cope (Cotype). 
Specimen No. 1421 (Carnegie Museum Catalogue of Vertebrate Fossils). —'This fine 
fossil is from the Niobrara Cretaceous of Hackberry Creek, Gove County, Kansas. 
The ex situ portions of the original skeleton, which had weathered out and were 
secured in more or less complete condition, include the left humerus, radius, ulna, 
: & / 
Fic. 1. Protostega gigas. Carnegie Museum Specimen, No. 1421, from Niobrara chalk of Hackberry Creek, Gove 
County, Kansas. Superior view of skull with the lower jaw and a hyoid, the right anterior border of the carapace and 
most of the right fore flipper, all in nearly natural position and still partially imbedded as collected on a single slab of 
the chalk matrix.  t. 
Skull. —pm., premaxillary ; m., maxillary ; n.0., external nares; p.f., prefrontal ; fr., frontal ; 0., orbital border ; 
p., parietal; s.o., supraoccipital ; 7., jugal ; q.j., quadratojugal ; sq., squamosal ; q., right quadrate. 
Lower Jaw. ae he dentalium ; a., angular; sr., surangular; sp., splenial; (h., hyoid). 
Carapace.— N., portion of right ala of nuchal ; 2r., second rib; Zm., 2m., first and second marginalia. 
Flipper.— H., humerus; R., radius; U., ulna; r., radiale(?); 7., intermedium ; w/., ulnare; p., pisiform; 1-5, 
first to fifth carpalia respectively ; I.—V., first to fifth metacarpalia. 
