CHELONID^). 51 



of the Loggerhead than to that of the Hawksbill and 

 apparently indicates an allied form, which may be at least 

 provisionally included in the same genus. The foramina 

 on the oral surface and also the two large ones on the 

 anterior border of the masseteric fossa of the ramus agree 

 closely with the existing species. On the inferior aspect 

 of the ramus there is, however, a prominence below the 

 masseteric fossa, which does not occur in the existing form, 

 and affords a good specific character. 



Bowerbank Collection. Purchased, 1865. 



43263. A large imperfect left scapulo-precoracoid provisionally 

 referred to this form ; from Sheppey. Nearly the whole 

 of the precoracoid is wanting. The specimen is somewhat 

 larger than the scapula of the largest recent skeleton of 

 Chelone mydas in the Museum. Judging from the 

 relatively small size of the coracoid and carapace in 

 Lytoloma erassieostatum and L. planimentum, this specimen 

 would be much too large to have belonged to either of 

 these species, and it is quite different from the corre- 

 sponding bone of the Dermochelyiclce. 



Presented by Dr. Kowalevsky, 1871. 



Genus LYTOLOMA, Cope \ 



Syn. Euclastes, Cope 2 . Puppigerus, Cope 3 (in parte). 



Glossochelys, Seeley 4 . Pac7iyrhynchus, Dollo 5 . 



Erquelinnesia, Dollo 6 . ? Osteopygis, Cope 7 . 

 ? Propleura, Cope 8 . 



Skull of the general proportions of that of Thalassochelys, with 

 the orbits and nares largely directed upwards, a narrow interorbital 

 bar, and an occipital shield. Palate flat, with very low alveolar 

 walls and no ridge ; pterygoids short, deeply emarginate, and in the 

 adult joined near the middle of the emargination by the boundary 

 of the posterior nares ; the ectopterygoid processes near their anterior 

 extremities. Palatal apertures of temporal fossse very wide ; posterior 



1 Trans. Amer. Phil. Soc. vol. xiv. pt. i. p. 144 (1870). 



2 Proc. Ac. Nat. Sci. Phiiad. 1867, p. 39. Preoccupied by the Coleopterous 

 genus Euclastes, Led. (1855). 



3 Trans. Amer. Phil. Soc. op. cit. p. 235. 



4 Ann. Mag. Nat. Hist. ser. 4, vol. viii. p. 227 (1871). 



5 Bull. Mus. E. Hist. Nat. Belg. vol. iv. p. 130 (1886).— Preoccupied. 



6 Geol. Mag. dec. iii. vol. iv. p. 393 (1887). — To replace the preceding name. 



7 Proc. Ac. Nat. Sci. Phiiad. 1868, p. 147. 



8 Trans. Amer. Phil. Soc. op. cit. p. 138. 



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