268 BULLETIN 189, UNITED STATES NATIONAL MUSEUM 



Evermann and Radcliffe, already referred to, presumably having been 

 supplied by R. E. Coker, who is quoted by the same authors as saying 

 of this fish, "Vocal powers well developed." Polla does not appear in 

 the list of commercial species for which statistical data are offered in the 

 report of the Mission (1943). It would seem, then, that it is of little 

 if any commercial importance. The Peruvian examples seem to 

 be identical with specimens from Panama Bay, with which they 

 were compared. 



Range. — Known from Baja California to northern Peru. 



Genus PARALONCHURUS Bocourt, 1869 



Body elongate; back rather narrow; head rather low, broad, blunt; 

 a row of slender barbels on inner edge of dentary bones, becoming 

 more crowded anteriorly, and forming a tuft at the chin; preopercle 

 with a ciliated membranous margin; mouth inferior, generally not 

 quite horizontal; teeth in the jaws small, in bands, the outer ones 

 sometimes more or less enlarged; gill rakers little developed, only 

 about 5 to 10 on lower limb of first arch; first dorsal composed of about 

 9 to 11 slender spines; second dorsal long and low, with about 24 to 36 

 soft rays; anal small, with 2 rather small spines, and about 7 to 9 soft 

 rays. 



Three species are included in the Peruvian collections studied. As 

 the series of scales are rather irregular, the enumerations given are only 

 approximately correct. The species herein discussed have been 

 placed in the genus Polyclemus Berg by some authors, who reserved 

 Paralonchurus for the Central American species petersi, which differs in 

 having larger pectoral fins; rather prominently enlarged outer teeth in 

 upper jaw; more or less definitely cycloid scales above lateral line, 

 which are ctenoid in the other species; and in having more numerous 

 rays (33 to 36) in the second dorsal. As these differences are mostly 

 a matter of degree, and as no useful purpose seems to be accomplished 

 by dividing this rather small group, I shall recognize only one genus^ 



KEY TO THE SPECIES 



a. Anal with 8 or 9 rays; first arch with 11 to 14 gill rakers on lower limb, and 

 7 to 9 on the upper one; second dorsal with a narrow sheath of scales at 

 base, the rest of fin naked; pectorals shorter than head, 4.1 to 4.3 in 



length peruanus (p. 269) 



aa. Anal with 7 rays; first arch with 6 to 8 gill rakers on lower limb, and 3 or 4 on 

 the upper one; second dorsal almost completely covered with scales. 

 b. Second dorsal with 24 rays; about 58 scales in a lateral series; pectoral shorter 

 than head, 5.1 to 5.25 in length; eye large, 4.75 to 5.0 in head. 



dumerilii (p. 270) 



bb. Second dorsal with 27 or 28 rays; 66 to 73 scales in a lateral series; pectoral 



about as long as head, 3.75 to 4.2 in length; eye very small, 5.6 to 6.8 



in head goodei (p. 271) 



