1916.] NATURAL SCIENCES OF PHILADELPHIA. 437 



some with several obscure or slightly darker transverse cross-bars. 

 Iris silvery, tinged brownish. Length 40 to 58 nun. Orizaba, 

 Mexico (F. Sumichrast). 



This species is closely related to P. pleuro&pilus (Giinther), and 

 appears to differ only in the coloration, in which the lateral dark 

 spots are fewer in number. The present species was originally 

 described 13 with "a narrow dark streak on under side of caudal 

 peduncle, "' a character not indicated on the figure, 14 which is evidently 

 a female. Meek also describes Heterandria pleurospilus as identical 

 with Giinther'- Girardinus pleurospilus, 1 ' but Regan claims, evi- 

 dently as they arc said to have "sides with 8 to 11 black spots .... 

 each about as large as eye, " that they are not Gunther's species, 16 but 

 H. lutzi Meek. Xone of these writers mention the conspicuous 

 black blotch so frequent in adult females at the front basal portion 

 of the anal fin, and well represented in Gunther's figure of G. pleuro- 

 spilus. 1 ' 7 



Leptorhaphis infans vWoolman). 



Orizaba. Mexico (F. Sumichrast). 



Phalloceros caudimaculatus (Hensel). 



Rio Grande do Sul, Brazil. Also several aquarium examples, 

 recently imported to Philadelphia, remarkable for their coloration. 

 Two are females and one a male. They are largely very pale 

 brownish, and below more whitish. Each scale on back with slight 

 or obscure narrow brownish edge. Sides of trunk and head with 

 silvery reflections. Slightly darker brownish streak down middle 

 of back. Fins all whitish, marked irregularly with jet-black blotches. 

 On middle of side, just below middle of depressed dorsal vertical 

 elliptical brownish blotch, obscure, about equal to eye-diameter. 

 Body and head also marked in striking contrast with irregular or 

 variable blackish blotches. Iris grayish. In no two individuals, 

 or even on each side of the same individual, are these color-patterns 

 alike. They are extremely prominent and render the fish very 

 attractive in the aquarium. Though this may be due in large 

 measure to domestication, certain wild examples also show similar 

 modifications, as I have found Gambusia affinis and Mollienisia 

 latipinna, from Florida, equally as contrasted as in the case of the 



13 Field Mus. Pub. 65, Zool. Ser., 1902, p. 106. Oaxaca, Cuicatlan and Venta 

 Salada, Mexico. 



14 L.c, 93, Zool. Ser., 1904, p. 149, fig. 47. 



15 Cat. F. Brit. Mus., VI, 1866, p. 355. Lago de Duenas, Guatemala. 



16 Biol. An. Centr. Pise, 1906-8, p. 99. 



17 Tr. Z. Soc. London, VI, 1868, p. 486, PI. 87, fig. 1. 



