24 PROCEEDINGS OF THE ACADEMY OF [Feb. 



BEMAEKS ON THE FOSSIL CETACEAN RHABDOSTEUS LATIRADIX Cope. 

 BY FREDERICK W. TRUE. 



The genus and species Rhabdosteus latiradix were first described by 

 Cope in 1867/ and were based on a rostrum from Charles County, Md., 

 near the Patuxent River, collected b}^ James T. Thomas. Three teeth 

 were also "with much probability" assigned to the species. Cope 

 remarked: "Joseph T. Thomas, the discoverer of this cetacean, tells 

 me that he has seen portions of the muzzle between two and three 

 feet long." 



No fm-ther original information regarding the species appears to 

 have been published until 1890, when Cope published figures of the 

 type specimen, as restored, and of a tooth. He remarked, however, 

 that the posterior parts of the maxillary and premaxillary bones "were 

 restored from a different specimen from that represented in the rest 

 of the figures."^ This "different specimen" was figured by Mr. Case, 

 in 1904, together with still another rostrum^ and the three teeth. 



From an examination of the three beaks, which were ver}'- kindly 

 placed in my hands for study by the authorities of the Philadelphia 

 Academy of Natural Sciences and Mr. Witmer Stone, it appears prob- 

 able that three species are represented. The rostrum figured by Mr. 

 Case in PI. 15, fig. 1, is the same as that described by Leid}^, in 1869, 

 as probably belonging to Priscodelphinus grandoevus} I have remarked 

 in a previous paper that the reasons for identifying the rostrum with 

 that species are unsatisfactory f but, however that may be, the rostrum 

 certainly does not belong to the same species as the one called Rhab- 

 dosteus latiradix by Cope, nor is it likely that it represents the same 

 genus. 



The "different specimen" mentioned by Cope in 1890, and figured 

 by Mr. Case in PI. 15, fig. 2, does not, in my opinion, belong to the 

 species latiradix, nor is it at all probable that it belongs to the genus 

 Rhabdosteus. 



1 Proc. Acad. Nat. Sci. Phila., 1867, pp. 132 and 145. 



2 Amer. Nat., 1890, p. 607, fig. 4. 



^ Rep. Maryland Geol. Surv., Miocene, 1904, PI. 15. 

 * Journ. Acad. Nat. Sci. Phila., Ser. 2, Vol. 7, 1869, p. 434. 

 ^ Smithsonian Misc. Colls., Quart. Issue, 50, Pt. 4, No. 1782, p. 451, January 27, 

 1908. 



