686 Bulletin 47, United States National Museum. 



1009. PLATYPCECILUS MACULATUS, Gunther. 



Head 3i ; depth 2i ; eye longer than snout, 3 in head. D. 10 ; A. 9 ; 

 scales 25-8. Body much compressed and elevated. Interorbital width f 

 length of head. Dorsal fin rather large ; anal small ; pectoral reaching 

 beyond root of ventral ; caudal peduncle short and deep. Olivaceous ; a 

 roundish black spot on middle of root of caudal ; a black spot on middle 

 of side of body; dorsal often densely spotted with black; margins of 

 anal and caudal black. Length li inches. Mexico : known from two 

 female specimens. (Gunther.) (maculatus, spotted.) 



Platypcecilus maculatus, GUNTHER, Cat., vi, 350, 1866, Mexico; (Coll. Sall6); JORDAN & GILBERT, 

 Synopsis, 348, 1883. 



1010. PLATYPCECILUS MENTALIS, Gill. 



Head 3; depth 3i; eye considerably longer than snout, 3 in head. 

 Body regularly compressed backward and moderately elevated, its 

 greatest depth being in advance of dorsal ; head less compressed than 

 the body ; the. width of the interorbital space less than i entire 

 length of head. Dorsal fin moderate, higher than long, its origin 

 about midway between tip of snout and middle of caudal ; anal small, 

 its origin opposite middle of dorsal ; caudal fin round, equal to length 

 of head, its depth at base f length of head ; pectoral extending consid- 

 erably beyond root of ventral ; ventral not reaching anal. Color, a uni- 

 form brownish olive, with no caudal spot ; a linear band crossing the chin 

 parallel with the lip; the dorsal with a deep, black, band-like spot near 

 the base crossing the anterior half. Brooks on Atlantic side of Isthmus 

 of Panama. (Gill); not seen by us. (mentalis, having a conspicuous 

 chin, mentum.) 

 PkUypaecilw mentalis, GILL, Proc. Ac. Nat. Sci. Phila., 1876, 335, Isthmus of Panama. 



315. HETERANDRIA, Agassiz. 



Heterandria, AGASSIZ, Amer Journ. Sci. Arts., 1853, 135,* (formosus; JtolbrooM). 

 Girardinus, POEY, Memorias, I, 383, 1855, f (metallicus). 



Body rather slender; mouth very small, the lower jaw very short, its 

 bones not united; snout short; both jaws with a single series of slender, 

 movable, pointed teeth ; scales rather large ; anal fin more or less in 

 advance of dorsal, in the male modified into an intromittent organ ; intes- 

 tinal canal elongate. Very small, viviparous, mud-eating fishes, among 



*The genus Heterandria was proposed by Agassiz (Amer. Journ. Sci. Arts, xvi, 135) in 1853, to 

 include certain Cyprinodonts which have the anal fin in the male modified. The two species (hol- 

 brooki and formosa) possessed by Agassiz (but not named until 1859), belong to different genera, 

 which correspond respectively to Poey's Gambusia and Girardinus. These generic names first 

 occur in the Memorias sob re la Historia Natural de la Isla de Cuba (I, p. 390). The date assigned 

 to their publication by Girard (Proc. Ac. Nat. Sci. Phila., 1859) is tho year 1851, which would 

 give each two years priority over Heterandria. This is, in fact, the date given on the title page of 

 the Memorias, but the volume was issued in parts, its publication extending over several years, 

 and the issue of the part containing Girardinus and Gambusia could not have been earlier than 

 1855. This is evident, as papers written in 1854 are printed in the text before it. In place either 

 of Gambusia. or Girardinus the name Heterandria must therefore be used. We have elsewhere 

 restricted it to the type of Girardinus, regarding Heterandria formosa, Agassiz, as its type. This 

 arrangement is in accordance with the wishes of Professor Poey, to whon. we are indebted for 

 the suggestion that Heterandria is prior to Girardinus. 



t These species were first named by Girard in 1859, after Agassiz's manuscript. Agassiz defined 

 the genus Heterandria with Chologaster, Zygonectes, and Melanura in 1853, in a letter to Prof. J. D. 

 Dana, published in the American Journal as above, but in this paper the species were not named. 



