212 BULLETIN 189, UNITED STATES NATIONAL MUSEUM 



of opercle; ventral fins a dirty white; other fins all more or less dusky; 

 second dorsal and anal quite dark, the latter with an indefinite white 

 margin, most pronounced anteriorly; pectoral darkest at base, black 

 on inner side. 



A single specimen, 135 mm. (105 mm. to base of caudal) long, was 

 dredged by the Mission in Sechura Bay, near Sechura. This specimen 

 (U.S.N.M. No. 127920) apparently represents a new species, though 

 it is closely related to H. leucurus (Giinther) , which as far as known in- 

 habits only Panama Bay. The Peruvian fish, although about 40 mm. 

 longer than any at hand from Panama, differs in so many characters, 

 some of which apparently cannot be ascribed to age, that it must be 

 regarded as distinct. The dorsal profile is higher and more evenly 

 convex than in Panama specimens. The arched part of the lateral 

 line is considerably shorter, being notably less than half the length of 

 the straight part in the Peruvian fish, whereas it is fully half the length 

 of the straight part in Panama fish. The second dorsal and anal are 

 quite differently shaped; as in the Peruvian example the rays in both 



Figure 47. — Hemicaranx sechurae, new species. From the type, 135 mm. long, Sechura 

 Bay, Peru (U.S.N.M. No. 127920). 



fins decrease gradually in length after about the sixth ray, none of the 

 rays in the posterior fifth or so of the fins being longer than the eye, 

 and the margins of the fins are nearly straight, whereas in the Panama 

 fish the rays decrease little in length to near the end of the fin, those 

 at about the beginning of the last fifth of the second dorsal being 

 about twice the length of the eye, and the margins of both fins are 

 strongly convex. Furthermore, in the Peruvian fish the caudal is 

 much more deeply forked, and the lobes are notably longer; the pec- 

 toral is much longer; and the bony scutes in the lateral line are much 

 more prominent. These last-mentioned differences may in large part 

 result from the greater age and size attained by the Peruvian fish. 

 The largest Panama fish at hand, and the ones described as Caranx 

 furthii (considered a synonym of H. leucurus) by Steindachner (1875b, 



