266 BULLETIN 189, UNITED STATES NATIONAL MUSEUM 



to first soft ray, its point not free, origin of fin rather nearer base of 

 ventral spine than vertical from end of second dorsal ; ventral inserted 

 about half an eye's diameter behind base of pectoral, quite blunt, 1.8, 

 1.75 in head; axillary process of ventral pointed, about as long as eye; 

 pectoral large, pointed, extending beyond tip of ventral (especially in 

 paratype), 1.25, 1.15 in head, 4.25, 4.1 in length. 



Color grayish brown above; sides silvery gray; lower parts pale, 

 mostly with dusky punctulations; an indefinite dark blotch on lower 

 part of side at tip of pectoral (missing on one side of the paratype) ; 

 fins all more or less dusky, at least distally, pectoral darkest on inner 

 side. 



This species is represented by two specimens, 330 and 445 mm. (275 

 and 367 mm. to base of caudal) long, both taken by the Mission with 

 a gill net in Paita Bay. The proportions and enumerations given 

 first in each instance apply to the smaller one (U.S.N.M. No. 128002), 

 which was selected as the type. This species is related to M. undu- 

 laius (Girard), which ranges northward from the Gulf of California to 

 California. The differences noticed when comparing the Peruvian 

 specimens with specimens of M. undulatus from California are indi- 

 cated in the parallel comparison that follows: 



M. rostratus 



Anal rays I, 7. 



Scales 78 to 85; rows between lateral 



line and first dorsal spine 5 or 6, the 



rows under middle of dorsal fins less 



strongly oblique. 

 Ventral 1.75 to 1.8 in head. 

 Pectoral reaching beyond tip of ventral, 



4.1 to 4.25 in length. 



M. undulatus 



Anal rays I, 8. 



Scales 87 to 100; rows between lateral 



line and first dorsal spine 7 or 8, the 



rows under middle of dorsal fins very 



strongly oblique. 

 Ventral 1.45 to 1.6 in head. 

 Pectoral reaching tip of ventral in large 



specimens, shorter in smaller ones, 



4.4 to 4.8 in length. 

 Caudal peduncle 3.0 to 3.1 in head. Caudal peduncle 3.5 to 3.75 in head. 



The name rostratus is given in allusion to the long snout. 

 Range. — Kjiown only from the type and one paratype from Paita 

 Bay, Peru. 



Genus UMBRINA Cuvier, 1817 



Body moderately elongate; back elevated; head rather low, broad, 

 conical; mouth horizontal, or nearly so, below the projecting snout; a 

 single short, thick barbel at tip of lower jaw; teeth in a band in each 

 jaw, the outer ones in upper jaw somewhat enlarged; margin of pre- 

 opercle finely serrate; first dorsal with 10 rather slender spines; second 

 dorsal long, with about 25 to 30 soft rays; anal small, with 2 spines, 

 and with about 5 to 8 soft rays. 



A single species is represented in the collections from Peru now at 

 hand. 



