DERMATEMYDID^. 233 



Genus COMPSEMYS Leidy. 



Little-known turtles belonging probably to the Dermatemydidae. Free surfaces of the 

 bones of carapace and plastron ornamented with small, close-set, enameled tubercles which 

 produce the appearance of shagreen. Neurals hexagonal, with the broader end forward. 

 Costals without distal prolongations into the peripherals. Sulci thread-like. The plastron 

 suturally articulated with the contiguous peripherals and sending up axillary and inguinal 

 buttresses to the costals. No evidences of mesoplastra. Inframarginal scutes probably on 

 the bridges. Vertebral scutes not greatly expanded. 



Type : Compsemys victus Leidy. 



The genus Compsemys was estabhsht in 1856 by Professor Leidy, to receive the scanty 

 remains which he named Compsemys victus. Later discoveries have added little to our 

 knowledge regarding the genus; altho it is evident that it is represented over a wide area of 

 territory and thru a considerable range of deposits, having been reported from levels rang- 

 ing from the Judith River beds to the Denver. The only characterization that Leidy gave to 

 his genus is exprest in the following words: 



The peculiarity of the specimens which has led to the proposal of the genus consists in their exterior 

 surface being closely studded with uniform granular tubercles, which give to them a shagreened appear- 

 ance, quite different from anything I have had the opportunity of seeing in other turtles. 



At a later time Professor Cope assigned to Compsemys Leidy's Emys obscurus and after- 

 wards returned it to Emys. At the same time he referred to Compsemys his own Adocus 

 lineolatus without explanation. These two species undoubtedly belong elsewhere. The 

 same verdict must be pronounct regarding the three species described by Cope in 1875 and 

 1876, from the Judith River beds, and called by him Compsemys ogmius, C. imbricurius, 

 and C. variolosus. In 1877 Cope described his Compsemys plicatula from the Jurassic of 

 Colorado, and there can be little doubt that his generic reference of the specimen was based on 

 the similarity of the sculpture to Leidy's species. Especially since Dr. Baur's description of 

 Cope's C. plicatula it has been regarded as representing the characters of Compsemys. How- 

 ever, there can be no doubt that plicatula belongs to a wholly different genus from victa, and 

 to another superfamily. Most of the references in scientific literature to the genus Compsemys 

 (for which see the writer's Bibliography and Catalogue of Fossil Vertebrata N. A., 1902, 

 p. 437) are to the genus as typified by C. plicatula and are therefore to be transferred to 

 Glyptops. When Baur (Proc. Acad. Nat. Sci. Phila. 1891, p. 412) states that the Laramie 

 forms of Compsemys show all the characters of the Jurassic form he seems to have had in mind 

 Cope's Compsemys variolosa, but this certainly has no mesoplastron. 



So far as at present known the only species to be assigned with any certainty to this genus 

 is the type, C. victa. It is probable that when the form that has been reported to occur in 

 the Judith River beds is better known it will prove to be a second species. 



Compsemys victa Leidy. 

 Plate 34, figs. 2, 3; text-figs. 291-295. 



Compsemys victus, LEIDY, Proc. Acad. Nat. Sci. Phila. 1856, p. 312; Trans. Amer. Philos. Soc., xi, 

 1860, p. 152, plate vi, figs. 5-7. COPE, Trans. Amer. Philos. Soc., xiv, 1869, p. 124; Seventh Ann. 

 Report U. S. Geol. Surv. Terrs., 1873 (i 8 74-)> P- f54! Bul1 - U. S. Geol. Surv., I, No. 2, 1874, p. 30; 

 Vert. Cret. Form. West, 1875, pp. 91, 261, plate vi, figs. 15, 16; ?Brit. N. A. Bound. Comm. Report, 

 l %75> PP- 333> 33^ ?Bull. U. S. Geol. Surv., in, 1877, p. 573. PCnoss, Monogr. U. S. Geol. Surv., 

 xxvii, 1896, p. 227. ?MARSH, Monogr. U. S. Geol. Surv., xxvn, 1897, p. 527. HAY, Bibliog. and 

 Cat. Foss. Vert. N. A., 1902, p. 437. 



Professor Leidy's type of the present species consisted of a neural; a considerable portion 

 of a costal, regarded as a fifth; and a fragment of the eighth costal. These are now in the 

 U. S. National Museum and bear the number 960. They were secured in deposits of probably 

 Laramie age, at Long Lake, North Dakota. The species was afterward reported by Cope 

 from supposed Laramie deposits in Colorado, now regarded as Arapahoe or Denver (Cross, 

 op. cit., pp. 227, 244), and with doubt from Judith River beds (Cope's Fort Union) and from 



