62 PROCEEDINGS OF THE ACADEMY OF 



sex. The origin of the dorsal fin is nearly equidistant between either extremi- 

 ties, whilst that of the anal is equidistant between the apes of the snout and 

 the insertion of the caudal fin. The ventrals hold the same position towards 

 the anal as in the female sex. The pectorals are proportionately longer. 

 The fins exhibit the same number of rays as in the female ; the anal differs in 

 its structure, inasmuch as the second and third rays are much stouter and 

 more elongated than the rest. 



The scales are well developed, deeper than long, posteriorly rounded off, an- 

 teriorly truncated, with radiating furrows upon the latter section alone. The 

 color is uniform olivaceous brown, lighter beneath than above ; the dorsal 

 and caudal fins exhibiting transverse blackish lines. 



Gambusia holbrooki is very abundant in ponds and ditches of fresh water of 

 South Carolina, and as already stated, was also collected in Florida. Speci- 

 mens from the latter locality are somewhat larger than those from South 

 Carolina. 



XII. The smallest fish so far known to inhabit fresh waters is Eeterandria 

 formosa, Ag. (MS.), which is found associated with the preceding species, in 

 South Carolina, where we have observed it ourselves, as well as in Florida, 

 whence Mr. Glover has brought specimens. When full grown the female 

 measures about an inch in total length, and the male six-eighths of an inch ; 

 the specimens from Florida being somewhat larger than those from South 

 Carolina. 



The body is compressed and fusiform in profile ; the head constituting a 

 little less than the fourth of the entire length. The snout is very short and 

 rounded off, the mouth quite protractile, with the lower jaw slightly project- 

 ing beyond the upper one. The eyes are very large and subcircular ; their 

 horizontal diameter entering about twice and a halt time or at most thrice in 

 the length of the side of the head. The dorsal fin is higher than long ; its an- 

 terior margin being nearly equidistant between the apex of the snout and the 

 extremity of the caudal fin. The anal is deeper than long, and somewhat 

 smaller than the dorsal. The ventrals are very small, short and broad, ex- 

 tending as far as the vent. The pectorals are elongated and project beyond 

 the origin of the ventrals. The fins in the male sex resemble those of the 

 female just alluded to, except the anal which is inserted more anteriorly, its 

 second and third rays being much more developed than the rest, thus giving 

 that an appendage-like appearance- The scales are comparatively very 

 large ; seven longitudinal series only being observed across the flanks of the 

 female sex. They are deeper than long, and furrowed upon their anterior sec- 

 tion alone. The ground color is olivaceous, or else yellowish brown above ; 

 the belly being of a light lemon tint. A black streak extends from the snout 

 along the middle of the flanks to the insertion of the caudal fin. From six to 

 eight brownish black vertical streaks may be observed along the sides inter- 

 secting the lateral streak, thus subdividing the surface of the body into quad- 

 rangular areas. A jet black spot exists at the base of the caudal fin, also at 

 the anterior margin of the dorsal and anal, except in the male sex in which the 

 latter fin is of a uniform yellowish tint. The caudal, ventrals and pectorals 

 are olivaceous and unicolor in either sex. 



The species thus briefly described, belongs to the genus Girardinus of Prof. 

 Poey. It is characterized by a protractile, rounded, and scarcely cleft month, 

 the lower jaw projecting somewhat beyond the upper one. There is but one 

 series of teeth which are approximated, moveable, slender at their base and 

 extremely acute. The anterior margin of the anal is situated somewhat in 

 advance of the dorsal, and varying in structure according to the sexes. The 

 caudal is rounded as usual. The branchiostegal rays are five on either side, 

 and the branchial orifices continuous under the throat. The intestine is slen- 

 der, elongated, convoluted, and the liver small.* 



* Memorias sobre la Historia Natural de la isla de Cuba, i. 1851, 390. 



[Feb. 



