1853.] 389 



6. Gila Grahamii, B. and G. Body subfiisiform, compressed. Head forming a 

 little less than the fourth of the entire length. General disposition of the fins 

 as in the preceding species, they differ in their structure as follow. 



D II. 10. A II. 10. C 10. I. 9. 8. I. 10. VI. 10. P 17. 



The disposition of the scales presents likewise differences which will be better 

 understood by figures. 



Head above and back, reddish brown ; upper half of sides greyish brown ; 

 inferior half of sides, greyish yellow. Abdomen, dull yellow, the whole with a 

 metallic redection. Fins unicolor, of the hue of the region to which they be- 

 long. 



Rio San Pedro, of the Gila. 



7. FtTNDULus GRANDis, B. and G. Body stout and very much compressed, 

 five inches long; the head forming the fourth of that length. Back bluish 

 black, sides greyish, with yellow spots. Beneath dull yellow. Dorsal and 

 caudal deep bluish black, margined with yellow; other fins yellow; the base 

 of anal spotted. Body and fins of the female unicolor. 



Formula of fins : D 11. A 12. C 2. I. 9. 9. I. 2. V 7. P 18. 

 Brackish waters in the vicinity of Indianola, Texas. 



8. Ftjndulus tenellus, B. and G. Body regularly fusiform, compressed, the 

 head forming two-ninths of the entire length. Eyes large. The back greyish 

 yellow, with small black dots irregularly dispersed. A black vitta extends 

 from the snout, across the eye, down through the sides, to the base of the caudal 

 fin. Beneath light yellow. Dorsal, anal and caudal sreyish with minute black 

 dots ; ventrals and pectorals yellow, without dots. Anterior margin of anal in 

 advance of the dorsal. Tip of ventrals almost reaching the anal. 



D 8. A 10. C 2. I. 8. 7. I. 1. V 6. P 12. 



Prairie Mer Rouge, La. (James Fairie, Fsq.,) and Russellville, Ky. 



9. Hydrargtra similis, B. and G. Back, bluish grey; sides and abdomen, 

 yellowish. Transverse narrow black bands in both sexes. Fins yellow, uni- 

 color in the female, dorsal, caudal and anal bluish grey. In the male the pos- 

 terior margin of the dorsal being provided with one blaek spot and two yellow 

 ones, one above, the other below the black. The caudal fin is posteriorly trun- 

 cated. 



D II. A 8. C 3. I. 8. 7. I. 2. V 5. P 18. 

 Brackish waters in the vicinity of Indianola. 



10. Cyprinodon elegaks, B. and G. The general form varies according to 

 the sexes ; the back in the male is very much arched, the body consequently is 

 deeper than in the female. The largest individuals are two inches and three- 

 eighths in total length. The bead forms two-sevenths of the length. Back deep 

 bluish black ; sides variegated with bluish black and greenish yellow. The 

 posterior edge of the caudal is maririned with black in the male. A black 

 spot, more conspicuous in the female, is observed on the posterior margin of the 

 dorsal. 



D 11. A 10. C 3. I. 8. 8. I. 2. V 6. P 14. 

 Rio Grande del Norte. 



11. Cypkinodov MACULARtris, B. and G. Body elHptically elongated, an inch 

 and six-eighths long; head short and rounded formmg one fourth of the entire 

 length. Above reddish brown, yellowish beneath, maculated with black ; spots 

 on the sides with an irregular tendency to arrange in vertical bands. Dorsal 

 blackish; other fins dull yellow, with a greyish base. 



n 8. A 10. C 3. I. 7. 6. I. 2. V 7. P 12. 

 From the Rio Gila. 



12. CvpRiNODON BoviNUS, B. and G. Has a general resemblance in shape to 

 C. elegans ; the head, however, is more truncated. The color in the male is 

 uniform blackish brown above ; yellowish green beneath. The fins are unicolor 

 except the caudal which has a blackish margin. The coloration of the female 

 differs from that of the male in having the lower portion of the flanks irregularly 



