THE SHORE FISHES OF PERU 89 



Head 3.5; depth 3.2; D. 18; A. 16; V. 8; P. 15; scales 40. 



Body moderately compressed, its greatest thickness somewhat 

 exceeding depth of caudal peduncle; ventral outline much more 

 strongly convex than the dorsal; caudal peduncle rather deeper than 

 long, 2.7 in head; head flat above; snout short, 4.5; eye 3.15; inter- 

 orbital 5.1; mouth moderately small, oblique; lower jaw projecting, 

 but not into dorsal outline; maxillary fully half width of eye, rounded 

 distally, not quite reaching middle of eye, 2.15 in head; mandible very 

 deep at side, 2.3 in head; teeth minute, present on premaxillaries 

 laterally, on margin of maxillary far beyond the gape, on palatines, 

 tongue, and pterygoids, but not on vomer; gill rakers slender, the 

 longest ones about two-thirds length of eye, 30 on lower limb, and 13 

 on the upper one (exclusive of the small ones on the forward pro- 

 jection), of the first arch; ventral scutes fairly strong, about 15 (partly 

 injured) before ventral fins and 14 behind them; scales firm,with 

 indented membranous edges; dorsal fin injured, its origin rather nearer 

 snout than middle of anal base; caudal injured; anal imperfect, low, its 

 origin somewhat nearer base of caudal than base of ventral, its base 

 2.0 in head; ventral inserted a little behind vertical from origin of 

 dorsal; pectoral imperfect, inserted about equidistant from tip of 

 mandible and base of ventral. 



Color grayish above; silvery on sides; indications of light streaks 

 along rows of scales; no opercular spot. 



The description is based on the type (U.S.N.M. No. 83156) of H. 

 -peruana, 92 mm. long to base of caudal, with injured fins. The 

 length is given as 105 mm. in the original description, wherein the 

 type locality shown is Callao, Peru, and the collector is the Wilkes 

 Exploring Expedition. Recent collectors did not take this species, 

 and Margaret Storey (1938, p. 51) questioned the correctness of the 

 locality given. I am unable to read what I assume to be the 

 original label with the specimen. 



The type of H. peruana was compared with specimens of H. thrissina 

 from Panama Bay, without detecting any significant differences. 

 Fowler and Bean seem to have beheved that the absence of an oper- 

 cular spot was important. However, Meek and Hildebrand (1923, 

 p. 186) pointed out that it was sometimes absent in Panama material. 

 More recently collected specimens from Panama, now at hand, con- 

 firm the observation. The large number of gill rakers ("about 18+ 

 36") given in the original description apparently is an error, as I am 

 able to count only 13 + 30, which brings the enumeration within the 

 range of specimens from Panama Bay. The following proportions 

 and enumerations are based on 11 specimens, 48 to 105 mm. (38 to 

 81 mm. to base of caudal) long, from Panama Bay: Head 3.4 to 3.8 

 in length; depth (increasing somewhat with age) 2.8 to 3.4; anal base 

 6.3 to 7.7; pectoral 4.6 to 5.0. Eye 2.9 to 3.5 in head; snout 4.3 to 

 4.8; interorbital 4.3 to 5.0; maxillary 2.1 to 2.2; mandible 1.9 to 2.2; 



