110 BULLETIN 189, UNITED STATES NATIONAL MUSEUM 



mandible, 2.95 to 3.4 in head; mandible sharply pointed, ending in a 

 small fleshy knob, laterally without definite folds of skin; eye 6.3 to 

 7.6 in head, or 2.0 to 2.35 in snout; mouth large, premaxillary reaching 

 far beyond eye, 1.6 to 1.7 in head; scales small, with membranous 

 borders, circulae well marked; dorsal fin high, the longest rays may 

 or may not reach tip of the last somewhat produced ray, 1.5 to 1.65 

 in head, origin of fin equidistant from adipose and anterior margin 

 of eye, or a little nearer the latter; adipose a little in advance of middle 

 of base of anal; caudal fin short, the upper lobe the longer, a little 

 longer than premaxillary; anal much lower than dorsal, its base a 

 little longer, 1.6 to 1.8 in head; inner rays of ventral nearly twice as 

 long as the outer one, reaching about halfway to origin of anal, 1.45 

 to 1.85 in head; pectoral short, rounded or somewhat pointed, variable, 

 failing to reach ventral, 1.85 to 2.25 in head. 



Color grayish above, silvery on side, pale underneath; some speci- 

 mens rather plain, others with pale spots or reticulations on head, the 

 spots extending backward to or beyond dorsal fin; some specimens 

 with rather definite dark lines along rows of scales above lateral line; 

 tip of mandible largely black; adipose partly black; dorsal, lower lobe 

 of caudal, and pectoral generally more or less dusky; fins otherwise 

 pale; a black spot at base of first ray of dorsal, and at base of upper 

 ray of pectoral usually present. 



The description is based on five specimens, 128 to 228 mm. (110 to 

 193 mm. to the base of the caudal) long, secured by the Mission, 

 mostly with an otter trawl in Paita Harbor, Sechura Bay, and at 

 San Lorenzo Island. The proportions, based on a sixth small speci- 

 men 55 mm. long, were not included, because they differ considerably 

 from the adult, and tend to confuse the comparison of proportions of 

 adult examples with other species. The following proportions per- 

 tain to the small example: Head 3.9 in length; depth 11.4; eye 5.75 

 in head, or 1.5 in snout; snout 3.75 in head; interorbital 2.7 in snout; 

 premaxillary 1.95 in head; pectoral 2.5. This small specimen is 

 pale, and retains traces of juvenile color markings, consisting of in- 

 definite dark spots on the ventral surface, short bars on the back, 

 and some black at base of caudal. 



I have examined the type (U.S.N.M. No. 41171) of Synodus 

 jenkinsi Jordan and BoUman, which is this species. However, at 

 least one of the paratypes (U.S.N.M. No. 41409) of S. jenkinsi is 

 S. sechurae, herein described as new. 



Range. — Gulf of California to Peru. The Galapagos Islands have 

 been included in the range given in published accounts. However, 

 I am unable at this time to find the source of that record. The species 

 previously was not recorded from Peru. 



