FISHES CYPR1NIDAE R1CHARDSONIUS LATERALIS. 



279 



brought alongside the body, their extremities reach nearly the origin of the ventrals. The 

 formula of the rays may be thus expressed : 



(Length, 5 inches.) D 2, 11 ; A 2, 18 -f 1 ; C 9, 1, 9, 8, 1, 8 ; V 1, 9 ; P 15. 

 (Length, 6 inches.) 2, 21 ; 16. 



The scales are of moderate development, somewhat irregular in their outline, with radiating 

 furrows upon their posterior half, all being directed backwards. The lateral line is deflexed along 

 the abdomen, bringing it much nearer the insertion of the ventrals than the base of the dorsal. 



The color of the dorsal region and upper aspect of the head is dark greyish brown or blackish; 

 the sides of the head, the flanks, and the belly, being silvery white. The dorsal, anal, and 

 caudal fins are greyish yellow ; the ventrals and pectorals of a light straw or yellowish tint. 



References to the figures . Plate LX, fig 1, represents Richardsonius balteatus, size of life, 

 from Fort Vancouver. Fig. 2 is a dorsal scale. Fig. 3, a scale from the lateral line. Fig. 4, 

 a scale from the abdominal region. 



List of specimens. 



2. BICHARDSONIUS LATERALIS, Grd. 

 PLATE LX, FIGS. 58. 



SPEC. CHAR. Head constituting the fifth of the total length. Snout sub-conical; jaws even ; posterior extremity of the 

 maxillary extending to a vertical line drawn behind the nostrils. Eye large and circular ; its diameter entering nearly four 

 times in the length of the side of the head. Anterior margin of dorsal fin a little nearer the extremity of the snout than the 

 fork of the caudal. Anal fin deeper than long and much shorter than the head. Caudal fin entering four times and a half in 

 the total length. Blackish b. own above ; metallic yellowish white beneath, with a black streak above the lateral line. Fins 

 unicolor. 



SYN. Richardsonius lateralis, GRD. in Proc. Acad. Nat. Sc. Philad. VIII, 1856, 202. 



This species is more of an elongated and fusiform aspect than R. balteatus. The head is 

 contained about five times in the total length. The pharyngeal teeth are five upon the outer 

 row, instead of four. 



The dorsal fin is sub-trapezoid also, higher than long, and somewhat nearer the extremity of 

 the snout than the fork of the caudal. The caudal itself is but moderately furcated. The anal 

 is deeper than long, nearly linear upon its external edge ; its anterior margin is equidistant 

 between the isthmus and the tip of the inferior lobe of the caudal. The ventrals are moderate 

 sized, posteriorly sub-truncated, their extremities reaching the vent, whilst their origin is nearly 

 equidistant between the extremity of the snout and the insertion of the caudal. The pectorals 

 are slender, but do not extend as far as the origin of the ventrals. The formula of the rays is 

 as follows : 



D 2, 9 + 1 ; A 2, 14 + 1 ; C 8, 1, 9, 8, 1, 7 ; V 1, 9 ; P 14. 



The scales are of moderate development, irregular in their outlines, anteriorly sub-truncated 

 and posteriorly rounded, exhibiting radiating furrows upon their posterior section only. The 



