42 U. S. p. R. R. EXP. AND SURVEYS — ZOOLOGY — GENERAL REPORT. 



1. CHIROPSIS CONSTELLATUS, Grd. 

 Plate XIX. 



Spec. Char. — Dorsal fins contiguous. Caudal fin posteriorly sub-concave. Anal exteriorly rounded, or convex. Scales on 

 the middle of the flanks conspicuously larger than elsewhere. Greenish-brown with groups of black dots on the anterior part of 

 body and sides of head. Pectorals densely doited witli black. 



Stk.— Cftiruj constellaius, Grd. Proc. Acad. Nat. Sc. Philad. VII, 1854, 141. 



The Tjody is sub-fusiform, compressed, deepest upon the thoracic region, and diminishing 

 posteriorly towards the base of the tail. The greatest depth is greater tlian the length of the 

 head and a little more than the fourth of the total length. The head is contained four times 

 and a half in the total length. The snout is sub-conical, the mouth moderately cleft, and the 

 extremity of the maxillary extends to a vertical line drawn somewhat inwardly to the anterior rim 

 of the orbit. The eye is sub-elliptical, its horizontal diameter being contained a little over four* 

 times in the length of the side of the head. The supra-orbital membranous flap is but mode- 

 rately developed, inserted nearly at right angle with the rim of the orbit, just above the posterior 

 tbird of the latter. The edge of the flap is fringed, though not so represented on the figure. The 

 branchiostegals are six on either side, and all well developed. The anterior dorsal is somewhat 

 higher than the second, though shorter upon its base. Both fins are contiguous, a feature 

 which the figure fails to represent. The posterior margin of the caudal is likewise sub-concave 

 or sub-emarginated, contrarily to its aspect in the figure published. The caudal fin enters 

 about six times and a half in the total length. The anal is nearly as long as the soft dorsal, 

 but not quite so deep. The tips of the ventrals and pectorals are nearly even, but do not extend 

 quite as far as the vent, which is situated somewhat in advance of the origin of the anal fin. 



Br. VI : VI ; D XXI, 25 ; A 24 ; C 5, 1, 8, 7, 1, 4 ; V I, 5 ; P. 19. 



The scales are disposed upon distinct series, which may be traced obliquely or longitudinally. 

 In shape, they are much longer than deep, somewhat irregular in their outline, and, generally 

 speaking, ciliated upon their posterior margin, in part (fig. 5), or whole (figs. 7 and 8). Diverging 

 furrows exist upon the anterior section of the scale only. We observe five lateral lines ; the 

 uppermost meets its fellow of the opposite side upon the occipital region ; hence they diverge 

 and follow the base of the dorsal fin as far as the middle of the soft portion, and there termi- 

 nate. The second of these lines starts from the nape, and runs along the dorsal region to the 

 base of the caudal fin. Anteriorly, four longitudinal series of scales may be observed between 

 the first and second lines. The third line occupies the usual region ; it originates above the 

 opercle, and, concurrent with the dorsal outline, runs towards the middle of the caudal fin. 

 Eight longitudinal series of scales may be counted within the area included between the second 

 and third lines, at their origin. The fourth line may be traced along the lower portion of the 

 flanks from the edge of the branchial fissures, passing beneath the base of the pectorals, hence 

 above the insertion of the ventrals, to disappear towards the peduncle of the tail. Thus the 

 area enclosed by the third and fourth lines eiubraces the entire side of the abdomen, which is 

 provided with the largest scales. Finally, the fifth line is observed along the mesial line of 

 the thorax and abdomen, commencing near the thoracic belt, branching off right and left one- 

 third of the way between the insertion of tlie ventrals and the origin of the anal, to terminate 

 near the base of the caudal. The figure does not give an accurate view of the direction of this 

 fifth line. Small scales may be observed upon the base of the caudal, dorsal, and pectoral fins. 

 The upper part of the head, the ojjercular apparatus, and the clieeks are densely covered with 



