THE SHORE FISHES OF PERU 161 



ec. Dorsal with 9 or 10 spines, and 10 to 13 soft rays (except Paranthias, 

 which has 20); anal with 7 to 10 soft rays. 

 i. Dorsal with 10 to 15 soft rays; 12 to 22 gill rakers on lower limb 

 of first arch; caudal not very deeply lunate, the lobes not sharply 

 pointed. 

 j. Scales small, about 80 to 110 oblique series above lateral line; 

 ventral fins inserted under or more usually behind base of 

 pectorals. 

 k. Body deep, compressed, depth about 2.25 to 2.5 in length; 

 maxillary with a distinct supplemental bone; dorsal with 

 about 10 soft rays; anal with about 9 soft rays. 



Hemilutjanus (p. 173) 

 kk. Body more elongate, depth about 3.0 to 4.0 in length; maxil- 

 lary without supplemental bone; dorsal with about 12 to 

 15 soft rays; anal with about 7 soft rays. 

 I. Head low and broad, scarcely deeper than broad; some 

 spines of dorsal bearing filaments (at least in adults); 

 12 to 15 gill rakers on lower limb of first arch. 



Cratinus (p. 174) 

 II. Head deeper, notably deeper than broad; some spines of 

 dorsal elevated (in adults) but not bearing filaments; 

 16 to 22 gill rakers on lower limb of first arch. 



Paralabrax (p. 176) 



jj. Scales larger, about 50 to 75 oblique series above lateral line; 



ventral fins generally inserted a little in advance of base of 



pectorals. 



TO. Serrae on margin of preopercle all rather small, none arranged 



in clusters; scales large, about 45 to 50 obhque series 



above lateralUne Prionodes (p. 181) 



mm. Serrae on margin of preopercle enlarged at angle, arranged 

 in 1, sometimes 2, clusters; scales smaller, about 60 to 75 



obhque series above lateral line Diplectrum (p. 184) 



ii. Dorsal with about 20 soft rays; about 25 gill rakers on lower limb 

 of first arch; caudal deeply lunate or forked, the lobes pointed. 



Paranthias (p. 189) 



aa. Dorsal with 2 or 3 spines; anal without spines; scales embedded, their margins 



not free; opercle above posterior angle attached to shoulder by a membrane. 



Rypticus (p. 192) 



Genus ACANTHISTIUS Gill, 1862 



Body elongate, compressed; mouth large; premaxillaries protrac- 

 tile; maxillary with a supplemental bone; teeth in jaws villiform, in 

 bands, some of the outer teeth more or less enlarged, present also on 

 vomer and palatmes; preopercle serrate, with strong antrorse spines 

 on lower border; opercle with three strong spines; gill membranes 

 separate; 7 branchiostegals; pseudobranchiae present; lateral line 

 complete; scales very small, mostly ctenoid; dorsal fin single, with 11 

 to 13 spines and 15 to 18 soft rays; caudal rounded; anal with 3 spines 

 and 7 to 9 soft rays; ventrals inserted below or behind base of pecto- 

 rals, close together, with a strong spine; pectorals rounded, with 19 to 

 21 rays. 



A single species is known from Peru. 



