T£STUDINIDJ3. 



4. Clirysemys troostii. 



Emvs troostii, Ilulhr. N. Am. Ilerp. i. p. 12M, pi. xx. (1842) ; Grmj, 

 Cat. Tort. p. 42 (1844) ; A. Than. Cat. Meth. Rept. p. 10 (1851) ; 

 Gnu/, Cat. M. Kept. i. p. 28 (l^o-O). 



Trachemys troostii, Aqass. Contr. N. H. U. S. i. p. 435 (1857) ; 

 Gin,/, 'Suppl. Cat. Sl'i. Rept. i. p. 48 (1870). 



rseudemys troostii, Cvpc, Check-Lut N. Am. Rept. p. 53 (1875). 



Shell subround, much depressed, ecarinate and smooth in the 

 adult, very slightly serrated behind ; nuchal almost linear. Plastron 

 slightly eraaigiiKite behind ; the longest median suture is that 

 between the abdominals, next comes that between the anals, shortest 

 of all that between the humerals ; axillary and inguinal shields 

 present. Head small, oval, and pointed : jaws as in C. scripta. 

 Digits broadly webbed, claws very long in the male. Tail nearly 

 one third the length of the shell in the male. (Jarapaco dusky, 

 tinged with green ; plastron brownish yellow, with a large, black 

 blotch on each shield ; these spots are liable to become blended or 

 altogether obsolete. Head dusky, with very obscure rays of 

 brownish yellow ; no bands on the upper surface of the neck. 



Length of shell 20 centim. 



Missouri, Illinois, Tennessee, Mississippi. 



I should have regarded the single specimen, type of Gray's E. 

 olivacea, as belonging to this species, were it not that the plastron is 

 ornamented all over with undulated dark bands somewhat as in C. 

 oregonensis. It may perhaps be considered a variety of C. troostii. 



? Chrysemys olivacea. 



Eniys olivacea, Gray, Cat. &/i. Rept. i. p. 30, pi. xii. c (1855). 

 Clemmys olivacea, Straiuh, Cfiehn. Uttid. p. 32 (1802). 

 Hedamia olivacea. Gray, Svppl. Cat. Sh. Rept. i. p. 36 (1870), and 

 An». &■ May. N. H. (4) x. p. 54 (1872). 



a. Ilgr. d , stffd. ? Dr. J. E. Gray [P.]. (Type.) 



5. Chrysemys hieroglyphica. 



Emys hieroglyphica, HoIhr.N. Am. Jlerp. i. p. Ill, pi. xvii. (1842) ; 



Gray, Cat. Tort. p. 26 (1844) (not specimen)} A. Dum. Cat. 



Meth. Rept. p. 12 (1851). 

 Pseudemys ? hieroglyphica, G)-ay, Cat. Sh. Rept. i. p. 34 (1855), and 



Svppl. p. 47 (1^70). 

 Ptychemys hieroglyphica, Ayass. Contr. Is. H. U. S. i. p. 434 



(1857). 

 Clemmys hieroglyphica, Strauch, Chelon. Sttid. p. 33 (1802), and 



Vert/i. Schildkr. p. 86 (1865;. 



SheU oval, much depressed, ecarinate and smooth in the adult, 

 posterior border serrated ; nuchal small, narrow ; first vertebral 

 shield urceolate. Plastron emarginate behind, the longest median 



