184 BULLETIN 189, UNITED STATES NATIONAL MUSEUM 



half of its lower margin weakly serrate ; opercle with three sharp spines ; 

 gill rakers on lower limb of first arch 12 or 13, the 3 anterior ones 

 very small; spines of dorsal low, increasing rapidly in length from the 

 first to the fourth, then decreasing, the fourth 2.6 in head; second 

 spine of anal a little stronger, but scarcely longer than the third, 

 about two-thirds to three-fourths as long as the longest soft ray; 

 pectoral reaching nearly to vent, 1.4 in head. 



Color dark gray; an indefinite dark longitudinal band on side; 

 5 or 6 dark cross bands extending downward from nape and base of 

 dorsal; inner side of gill covers deep black; fins, especially the ventral, 

 quite dark (dark gray in life), without spots or stripes. 



No specimens are at hand. The description was compiled and 

 condensed after Steindachner (see reference above), who had one 

 specimen, 195 mm. long, from Paita, Peru, and a second specimen from 

 the "coast of Chile." The proportions given apparently are not 

 based on accurate measurements, as the author prefaces them in part 

 with "circa." 



Range. — Coasts of Peru and Chile. 



Genus DIPLECTRUM Holbrook, 1855 



Body elongate, moderately compressed; opercle usually armed with 

 one cluster of strong divergent spines at its angle, occasionally with 

 two clusters; snout and interorbital space naked; lateral line com- 

 plete; scales moderately small, firm, ctenoid; dorsal rather low, with 

 10 spines and usually with 12 soft rays; caudal lunate to slightly 

 forked; ventrals inserted under or a little in advance of base of 

 pectorals. 



Two species are included among the specimens from Peru now before 

 me. Three others, D. eury plectrum, D. macropoma, and D. pacificum, 

 may be expected there. All apparently are fairly common in Panama 

 Bay, and of the first one named there is a specimen in the U. S. National 

 Museum (No. 41148) from the Galapagos Islands. D. macropoma was 

 reported from Ecuador by Meek and Hildebrand (1925, p. 475). 

 However, it appears now that the record was based on a general label 

 "Ecuador to Panama" attached to a jar in the U. S, National Museum. 

 A check of each specimen contained therein reveals the fact thai they 

 are all from Panama Bay. A key to the species named, and to the 

 two included in the Peruvian collections studied, is given below. 

 No descriptions of the species not actually known to occur in Peru are 

 offered but are included in Meek and Hildebrand (1925, pp. 472-478). 

 The key will aid in showing the relationship of the Peruvian species, 

 especially the new one herein described, to the neighboring species. 



KEY TO THE SPECIES 



a. Anal fin normally with 8 soft rays; 13 to 16 gill rakers on lower limb of first 

 arch; eye large, 3.3 to 4.0 in head; caudal peduncle slender, 3.5 to 3.8 in 

 head; base of soft dorsal dusky to black. euryplectrum 



