430 G. R. Wieland — Upper Cretaceous Turtles. 



Art. XLIY. — Structure of the Upper Cretaceous Turtles of 

 New Jersey :* Agomphus / by Gr. R. Wieland. 



The genus Agomphus was first proposed by Cope for the 

 reception of Leidy's Emys jinnus and Adocus petrosus and 

 Adocus turgidus^ all of which are based on very fragmentary 

 and scanty remains from the Upper Cretaceous marl beds of New 

 Jersey, indicating a genus of heavy shelled turtles next related 

 to Adocus. Two of these original types, A. petrosus and A . tur- 

 gidus, are now conserved in the Cope Collections in the Amer- 

 ican Museum of Natural History, where the writer has been 

 extended the courtesy of seeing them, together with the allied 

 Adocus pectoralis Cope. An additional type from the 

 Tertiary of Georgia, Amphiemys oxystemum,% is no doubt 

 correctly referred to Agomphus, but has not been accessible. 

 Since the brief descriptions unaccompanied by figures were 

 given by Cope, the only addition to the very meager knowledge 

 of Agomphus was made by Baur,§ who briefly noted in addi- 

 tion to the close relationship to Adocus and inclusion in the 

 Adocidse as next related to the existing Central American 

 Dermatemydidse, the peculiar costiform processes and the 

 interesting fact that Agomphus includes forms with relatively 

 the heaviest carapace and plastron known. These latter facts 

 were doubtless based on the specimens of the Marsh Collec- 

 tion obtained about the same time as the Leidy and Cope 

 material, but never formally described or further mentioned 

 although now found to make possible a complete description 

 of the structure of the. carapace and plastron, and to include 

 at least two new species and a topotype as follows : 



Agomphus tardus Wieland (sp. nov.). (Figures 1-1.) 



By far the best specimen of the Marsh collection referable to 

 the genus Agomphus is that numbered 774 (Accession No. 323), 

 and now made the type of the new species A. tardus. This 

 fine fossil was obtained from the Pern ber ton marl pits at Bir- 

 mingham, Burlington County, New Jersey, in 1869. It is of 

 especial interest as affording the structural characters of the 



* The first paper of this series, on Adocus, Osteopygis, and Propleura, 

 appeared in this Journal, vol. xvii (pp. 112-132, pi. I- IX), Feb. 1904, and 

 the second on Lytoloma, in vol. xviii (pp. 183-196, pi. V-VTII), Sept., 1904. 



f The description of these forms under the generic name Emys appears on 

 pages 125-8 of Cope's Synopsis of the Extinct Batrachia, Eeptilia and Aves 

 of North America. Philadelphia, August, 1869. — Agomphus in Suppl't, 1871. 



\ On a New Species of Adocidse from the Tertiary of Georgia ; by E. D. 

 Cope. Proc. American Phil. Soc, vol. xvii, July, 1877, pp. 82-4. 



§ Notes on some little known American Tortoises (on pp. 429 and 430), 

 Proc. Acad, of Natural Sciences, Philadelphia, 1891 (pp. 411-430). 



