1). RivuLu^. 327 



9. mVULUS. 



Rivulus, Poe\j, Mem. Cub. ii. p. 307. 



Cleft of the mouth small, with the upper jaw but slightly pro- 

 tractile, snout not produced ; both jaws with an outer series of 

 curved teeth and an inner band of vilHform teeth. Scales of mo- 

 derate size. Dorsal fin shorter than, and behind, the anal. Sexes 

 not differentiated by modification of the anal fin. Intestine very 

 short and simple. Air-bladder none. Frequently an oceUated spot 

 on the upper part of the root of the caudal fin. 



Tropical America. 



1. Rividus cylindraceus. 



Poey, 3fem. Cub. ii. p. 308. 



B. 6. D. 9. A. 12. L. lat. 40. 



The height of the body is contained five times and one-half in the 

 total length (with the caudal), the length of the head three times 

 and three -quai'ters ; the diameter of the eye is more than the length 

 of the snout, and two-sevenths of the length of the head. The 

 origin of the dorsal fin is on the third fifth of the total length. 

 Caudal truncated. Greenish, with an oceUated, black, yellow- 

 edged spot on the upper part of the root of the caudal. {Poey.) 



Havanna. 



2. Rivulus urophthalmus. 

 D. 6. A. 9. V. 6. L. lat. 38. L. transv. 11. 



Trunk subcylindrical, head depressed and obtuse, tail compressed. 

 The length of the head is two-ninths of the total (without caudal) ; 

 the height of the body two -elevenths. Snout rounded, with the 

 jaws equal in length, nearly as long as the eye, the diameter of 

 which is one-fourth, or, in the younger examples, more than one- 

 fourth, of the length of the head. Mandible as long as the eye. 

 Interorbital space quite flat, its Avidth being half the length of the 

 head. Dorsal fin situated far backwards, its origin being opposite 

 to the end of the anal fin, and its distance from the gill-opening ex- 

 ceeding double the length of the head. Ventral fins very small, 

 about as long as the eye, but reaching the vent. Pectoral termi- 

 nating at a great chstance from the ventral. Light-brownish olive; 

 caudal striolatcd with brown. Generally a black, white-edged ocellus 

 on the upper part of the root of the caudal. 



Brazil. 



a-d. Males, from 1| to 2 inches long. Para. Purchased of Mr. 

 Stevens. 



3. Rivulus micropus. 



? Fundulus micropus, Steindachner, Sitzgsber. Akad. Wiss. Wien, 1863, 

 xlviii. p. 184. 



Closely allied to Fundulus urophthalmus. 



D. 8. A. 16. V. 6. L. lat. 36. 



The length of the head is one-fourth of the total (without caudal). 



