230 BULLETIN 18 9, UNITED STATES NATIONAL MUSEUM 



KEY TO THE GENERA 



a. Anal fin short, with 7 to 9 soft rays; dorsal with 10 or 11 spines; upper jaw 

 with 2 to 4 canines anteriorly; villiform teeth on palatines and tongue. 



Lutianus (p. 230) 

 aa. Anal fin longer, with 11 to 18 soft rays; dorsal with 12 or 13 spines; no canine 

 teeth in jaws, and no teeth on palatines or tongue. 

 6. Anal fin with about 17 or 18 soft rays; dorsal with about 17 or 18 soft rays; 



margin of preopercle without bony serrae Xenichthys (p. 232) 



lib. Anal fin shorter, with about 11 to 13 soft rays; dorsal with 13 to 15 soft rays; 

 margin of preopercle rather strongly serrate Xenistius (p. 235) 



Genus LUTIANUS Bloch, 1790 



Body elongate, compressed; back more or less elevated; head long, 

 generally pointed; nostrils close together, without tubes; mouth large; 

 each jaw with a band of teeth, the outer ones usually enlarged, the 

 upper jaw with 2 to 4 canines anteriorly; villiform teeth on vomer, 

 palatines, and tongue; margin of preopercle serrate; gill rakers rather 

 few; scales moderate, ctenoid, usually extending on base of soft dor- 

 sal and anal; dorsal fin continuous, with 10 or 11 spines; caudal fin 

 emarginate or with a shallow fork; anal with 3 rather strong spines 

 and 7 to 9 soft rays. 



Two species certainly belong to the Peruvian fauna. Tortonese 

 (1939b, p. 298) recorded L. steindachneri (Jordan and Gilbert) from 

 Callao, Peru, and from Rio de Janeiro, Brazil. It is extremely 

 doubtful that the specimens from the two localities are identical. I 

 cannot determine the species from the brief account given by 

 Tortonese. 



KEY TO THE SPECIES 



a. Rows of scales above lateral line parallel with it, about 47 vertical series 

 above lateral line; teeth on vomer in an anchor-shaped patch, with a long 



backward extension argentiventris (p. 230) 



aa. Rows of scales above lateral line not parallel with it, very oblique, about 56 

 vertical series above lateral line; teeth on vomer in a roughly diamond- 

 shaped patch, with only a slight backward prolongation peru (p. 231) 



LUTIANUS ARGENTIVENTRIS (Peters) 



Mesoprion argentiventris Peters, 1869, p. 704, Mazatldn, Mexico (original descrip- 

 tion) . 



Lutianus argentiventris Meek and Hildebrand, 1925, p. 513, Panama Bay 

 (synonymy; description; local abundance; range). 



Head 2.6, 2.75; depth 2.3, 2.4; D. X, 14, X, 14; A. Ill, 7, III, 8; 

 P. 16, 16; scales 47, 47. 



Body rather compressed, its greatest thickness about half its depth; 

 back elevated; profile in advance of dorsal gently convex; head com- 

 pressed; caudal peduncle short, quite compressed, 2.9, 2.95 in head; 

 snout long, pointed, 3.3, 3.4 in head; eye 3.2, 3.3; interorbital 5.75, 

 6.5; mouth large, slightly oblique, terminal; maxillary reaching front 

 of pupil, 2.4, 2.55 in head; teeth mostly small, pointed, a few rather 



