THE FISHES OF PORTO RICO. 
97 
Known only from mountain springs in Porto Rico; here described from the original type, the 
only known example, as the other specimens possessed by Cuvier & Valenciennes belong to a species 
of Gcimbusia. This species was not obtained by us, but is recorded from Porto Rico by Poey. 
Fundulus fonticola Cuvier & Valenciennes, Hist. Nat. Poiss., XVIII, 198, 1846, Porto Rico; Poey, Fauna Puerto-Riquefia, 
342, 1881; Jordan & Evermann, 1. c., 643, 1896. 
Genus 32. PCECILIA Bloch & Schneider. 
Body oblong, often rather deep; mouth small, transverse, with weak jaws; teeth small, in narrow 
bands, the outer series in each jaw being usually enlarged, curved, movable, and with brown tips; 
lower jaw not prominent, bones movable. Scales large. Dorsal fin rather small, of 7 to 11 rays; anal 
fin short, in female nearly opposite dorsal, in males advanced and modified into a sword-shaped intro- 
mittent organ. Vertebra; about 28. Intestine long. 
Numerous species, mud-eating and viviparous, inhabiting the West Indies, Mexico, and South 
America. The genus differs from Mollienisia only in the smaller size of the dorsal, which usually has 
9 or 10 rays and is nearly opposite the anal in the female, but behind it in the male. 
а. Scales very large, 23 to 25 in a lengthwise series; coloration plain; dorsal and anal dotted. 
б. Dorsal rays 7; anal rays 8; coloration plain, fins dotted vivipara, 47 
bb. Dorsal rays 9; anal rays 8 giUi 
aa. Scales moderate, 28 to 32 in a lengthwise series. 
c. Base of caudal with a black ocellus pavonina 
cc. Base of caudal without distinct black ocellus. 
d. Dorsal and anal each with 10 or 11 rays; scales 30 to 32,-10; depth 3 to 3.33 in length; side with two rows of black 
dots vittata 
dd. Dorsal with 7 to 11 rays; anal rays 6 to 9. 
e. Body rather robust, depth in adult more than one-fourth length mexicana; 
thermalis; chisoyensis; pelenensis; sphenops; dovii; boucardi; vandepolli; dominicensis; melanogaster; spilurus 
ee. Body rather elongate, depth in adult not more than one-fourth length elongata 
47. Poecilia vivipara (Bloch & Schneider). 
Head 3.6; depth 3.5; eye 3.5; snout 4.2; interorbital 1.8; D. 7; A. 8; scales 25,-8. 
Body stout, compressed posteriorly; head depressed, flat; mouth small, jaws weak, lower pro- 
jecting; teeth small, in a narrow band in each jaw, outer series greatly enlarged, curved, movable, tips 
brown, those of inner series of short, blunt papillae; greatest width of body at pectorals about 1.2 in 
head; caudal peduncle greatly compressed 7 or 8 times in its least depth; origin of dorsal fin in female 
somewhat posterior to that of anal, a little nearer snout than tips of caudal fin; dorsal and anal fins 
small, the rays short; pectorals and ventrals short; scales large; intestinal canal long and convoluted. 
Color, olivaceous, paler below; borders of scales brownish; a dark bar across anterior part of 
opercle, meeting its fellow below; dorsal fin with a broad black bar, plainest on posterior rays, some- 
times not evident on anterior rays; caudal with many fine dark specks, faint traces of two dark crossbars; 
an irregular black blotch on base of upper caudal rays and a similar one on lower, these sometimes 
indistinct. The males differ somewhat from the females in color. The black at the base of the caudal 
is more distinct, and the body is crossed by some 10 or 12 indistinct brownish bars. 
The male also differs from the female in having the anterior rays of the anal modified into a long, 
somewhat curved intromittent organ, the length of which is usually about equal to length of head; the 
anal is situated much farther forward, its origin being nearer tip of snout than base of caudal; the 
ventrals are also much lengthened, about 1.3 in head. 
This little fish has been recorded from Brazil, Guiana, and Martinique. It was found near Ponce 
and Fajardo and at Arroyo and Hucares. At the latter place 422 specimens were obtained February 
14 in a small brackish- water lagoon, where it was associated with Dormitalor maculatus and the young of 
Tarpon atlanticus. They most frequented the shallow water along the edges of the lagoon, where they 
swarmed in great numbers and were easily caught in a small hand-net. Of the 422 examined only 34 
were males. The largest females are about 2 inches in total length, the males about 1.44 inches. At 
Fajardo 71 were taken, of which only one was a male. These were evidently adults, some being 3 
inches long and most of them over 2 inches. Some of the females contained well-developed young. 
Poecilia vivipara Bloch & Schneider, Syst. Iehth., 452, pi. 86, fig. 2, 1801, Surinam; Jordan & Evermann, 1. e., 691, 1896. 
Poecilia surinamensis Cuvier & Valenciennes, Humboldt, Observ. Zool., II, 158, 1817, Surinam. 
Poecilia schneideri Cuvier & Valenciennes, Hist. Nat. Poiss., XVIII, 135, 1846, Surinam, 
F. C. B. 1900—7 
