1892.1 ^^ [Baur. 



Brogniart, who proposed the Latin name "Einydes" in 1805 for 

 DiimLTil's Frencli name " les Emydes," had given the following species 

 as belonging to it : E. ferox, E. rostrata, E. matamata, E. lutaria, E. 

 pensylvanica, E. dausa. 



E. ferox and E. r ostratu 'belong io IVionyx GeoSroy, 1809 ; E. matamata 

 to C/ielus Duraeril, 180G ; Chelys Oppel, 1811. 



It was Merrem * who divided the remaining species of Erays into two 

 groups, t 



(a) Emys — 



" Diglti distincti, unguibus acutis. 

 Rostrum corneum. 

 Sternum immobile." 



* Merrem, Blasius, " Versuch eines Systems der Amphibien," Marburg, 1820, pp. 22, 27. 



Merrem places the Testudo lutaria, with the following synonyms : Tesfudo lutaria L., 

 T. orbicularis {?) L., T. europwa Sclmeid., T. caspica Gmel, among his Emys, not knowing 

 that in tliis form the anterior part of the plastron is movable. 



1 1 have to say, however, that Kaflnesque had already, five years before, reached the 

 same conclusion in a book which is very rare, but of which my friend, Mr. S. Garman, 

 has a copy. I have to thank Mr. Garman for copying for me the part relating to the 

 Testudinata. The title of the book is "Analyse de la Nature ou Tableau de I'Univers et 

 des corps organises," Palerme, 1815. On page 75 we find : 



" Crypfephia. Les Cryptephiens. 



"Carapace inf(5rieure a 1 ou 2 valves mobiles; enfermaut les membres comme dans 

 une boite. 



"G. 3. Cheliphus R. ; 4. TJronyx R. ; 5. Didida R. ; 6. Monodida R. 



" Emydania. Les Emydiens. 



"Carapace ni coriace, ni a valves mobiles, pieds S. doigts libres ou palm6s. 



"G. 7. EinydaR., Emys Dum..; 8. Chemelys R. ; 9. Chdopus R. ; 10. Chelyda R., Chelys 

 Dum.; 11. Clidiurus B.." 



Unfortunately Rafinesque did not give the names of any species with the new genera, 

 nor did he give any characters. From a later paper, which was written in 1816, but not 

 published before 1832, we receive some information by Rafinesque (Rafinesque, C. F. . 

 " Description of Two New Genera of Soft-shell Turtles of North Axnerica.,' 'Atla7ilic Journal 

 and Friend of Knowledge, Vol. i, No. 2, Philadelphia, summer of 1832, pp. 64, 65. 



" Cheliphus Raf. Water turtles with valved shells, 5 claws and toes to all the feet. 



" Vronyx Raf. An anterior valve to the shell, toes and claws 5 and 4, tail with a claw. 

 T. sco)-pioides, etc. 



" Didida Raf. Bivalve lower shell, toes 5 and 4. Type T. clausa, odorata, etc. 



" Monodida Raf Lower shell valvular anteriorly, toes 5 and 4. T. retziana, etc . 



" Chemelys Raf. Warty scales, no valves, 4 toes to all the feet. T. verrucosa, etc. 



" Chdopus Raf. No valve, toes not palmated 4 and 5. T. punctata, etc. 



" Cheliurus Raf. No valves, feet palmated, a long scaly tail. T. serpentina, etc." 



The group with movable valves, named Cryptephia by Rafinesque, contains, there- 

 fore, the genera, Sternothserus = CtLeliph\is; Ci«oster;iMm = Uronyx = Monoclida; Cistudo 

 = Dldicla, part. 



The group in which the valves are not movable, named Emydania by Rafinesque, 

 contains the genera Emys = Emyda ; Clemmys = Chemelys = Chelopus ; Chdydra = 

 Cheliurus. 



PltOC. AMER. I'HILOS. SOC. XXX. 137. F. miNTED MARCH 5, 1892. 



