22 CASE. [VoL. XIV. 
In 1873 Riitimeyer (17) disregarded Cope’s classification of 
two years previous, and placed Dermochelys among the Pznnata. 
In 1886, the same year as Dollo’s first paper, Baur published 
anote in the Zoologischer Anzeiger (19), in which he claimed that 
the separation of Dermochelys from the Chelonitdae was abso- 
lutely artificial. He maintained his position in papers appearing 
at intervals from 1888 to 1893 (20-26). 
Zittel (27) in his text-book, and later Dames (28), disregarded 
the group Azheeae, the former considering the Dermochelyidae as 
a family of the Cryptodzra. 
There are then at present three views as to the position of 
Dermochelys. (1) It is closely related to the Cheloniidae, being 
merely a specialized form. (2) It is the sole representative of 
a group equal in rank to all the remaining Testudines. (3) It 
is the representative of a group of equal rank with the Z7zony- 
choidea, Cryptodiva, and Pleurodira+ 
Paleontology alone can decide which of these theories is 
correct, and, fortunately, a turtle from the middle cretaceous of 
Kansas, Protostega Cope, is known, which from its intermediate 
form affords most valuable evidence in completing the phylogeny 
of the existing sea turtles. This paper is concerned in describ- 
ing additional remains of this animal, and discussing its 
relationships to allied forms. 
Description of Protostega and Comparison with Related 
Forms. 
The material used in the following descriptions of Protostega 
consists of two specimens, both from the Niobrara cretaceous 
of Kansas. The first and larger specimen comprises the 
1 It may be of interest to give here the synonymy of Dermochelys. 
1816: Dermochelys, Blainville, Bull. des Sciences par la Société philomatique 
de Paris, année 1816, p. 119 (wrongly printed 111). (See Baur’s discussion of 
the names Dermochelys, Dermatochelys, and Sphargis, Zool. Anzeiger, no. 270, 1888.) 
1820: Sphargis, Merrem, Versuch eines Systems der Amphibien, p. 19. 
1822: Coriudo, Fleming, Philosophy of Zoology, vol. ii, p. 271. 
1828: Scytina, Wagler, Oken Isis, 1828, part 2, p. 861. 
1829: Dermatochelys, Wagler, Nat. Syst. Amphib., S. 133. 
1832: Chelyra, Rafinesque, Atlantic Journal and Friend of Knowledge, vol. i, 
no. 2, Philadelphia, Summer of 1832, p. 62. 
