Amphibians and Reptiles from Porto Rico and the Virgin Islands. 15 



Alsophis rufiventris Dumeril and Bibron. 



One from the Virgin Islands, from which the species has not been pre- 

 viously recorded. Ventrals 212, subcaudals 92, anals 2, scales transversely 

 over back 23. Length 943 mm. 



EMYDID^E. 

 Pseudemys palustris (Gmelin). 



A series of 10 very interesting examples from Guanica Lake, Porto Rico. 

 On first examination they appeared to represent two distinct species, and it 

 appears that two very great extremes of color variation occur in Porto Eico. 

 Dr. Stejneger pointed out in 1902 that "there are indications at hand that 

 there may be some constant differences between those inhabiting the different 

 islands, but the material at my disposal is not sufficient to warrant an attempt 

 to separate them." 



Later Dr. Barbour says: "There are specimens at hand from Jamaica (type 

 localitjOj Cuba, Haiti, and Porto Rico. They do not, however, vary in such 

 a way as to warrant the designation of varieties confined to each island. 

 Stejneger and I (Bull. M. C. Z., 1910, 52, p. 301) had both expected that 

 such subspecies might be defined. As yet, however, the material available 

 for study is very meager. The species is very shy, and is usually confined 

 to lowland muddy pools." 



Thus, as little appears to be known concerning this species, a few notes on 

 the variation are given below. All my examples Avere secured in the lowland 

 lake at Guanica. Dr. Stejneger's figures 185 and 186 represent what may be 

 considered tj'pical (in a restricted sense) of palustris. This shows specimens 

 which have the pale lengthwise lines on the sides and lower surf ace of the head. 

 In this form the carapace is more of a uniform color, without dark blotches 

 or spots, and the plastron may be marked with dark lines along the sutures of 

 the plates, which may vary to very obsolete or even be wanting. About 7 

 of my examples, representing both sexes of this form, are in the collection. 



The remaining three specimens exhibit a different pattern of coloration. 

 They also differ in having the front claws a little longer than the longest of 

 the preceding. The carapace in all is decidedly paler over and about the 

 anterior third than the rest of its extent, shov/ing but few markings, and these 

 now obscure, though the sutures of all the plates are conspicuously blackish. 

 The sutures of the plastron and all the lower marginal plates of the carapace 

 are also marked with blackish. The carapace is also largely speckled or 

 blotched with darker. The color-pattern of the head is strikingly different 

 from the other specimens and is shown everywhere with narrow blackish 

 wavy or vermiculated lines, often broken or irregular. The feet are similar. 



The latter variety was first noticed by Gray as Emijs vermiculata,^ and the 

 type locality given as tropical America. I have not seen his subsequent plate,^ 

 though under Trachemys rugosa he gives^ the following description of "Emys 

 vermiculata Gray" : "Shell 7| in. Back brown, closely black-dotted; sternum 

 and under side of margin very closely spotted. Sternal shields dark edged." 

 The locality is given as the AVest Indies. Sowerby and Lear figure the 

 Emys rugosa,'^ a fairly good representation of the present variety. 



The interesting figure by Cocteau^ agrees with the above in the speckled 

 carapace and dark-edged sutures of the plastron. The head is streaked as in 

 the examples here allowed as typical palustris. 



'Cat. Tort. Brit. Mus., 1844, p. 25. "Tort. Terrap. Turt., 1872, plates 42, 43. 



2Cut. Shield Rep. Brit. Mus., 1855, plate 13. ^jjist. Nat. Cuba, Sagra, Rept., 1844, plate 2. 

 'Haud-List Shield Rept. Brit. Mus., 1876, p. 46. 



