92 BULLETIN 95, UNITED STATES NATIONAL MUSEUM. 



Third dorsal spine longest, 1.88 in head; soft dorsal low; caudal 

 deeply forked, longer than head; second anal spine longer and 

 stronger than the third, 2.13 in head ; dorsals and anal inclosed in a 

 scaly sheath; ventrals reaching to posterior border of vent, 1.45 in 

 head ; pectorals longer than head, tips reaching vertical from origin 

 of anal, 0.94 in head. Scales large, regular ; lateral line parallel with 

 back. 



Color in alcohol: Silvery, dusky on back, sides crossed by 7 or 8 

 broken, dusky, vertical bars; fins dusky; tips of spinous dorsal 

 membranes black. Described from an individual 12. 7 cm. in length 

 from Eten. 



Regan states that this species differs from the Atlantic represent- 

 ative (X. cineruin) in the fewer scales, larger head, longer maxil- 

 lary, and longer second anal spine, whilst the bars on the sides are 

 usually more numerous. 



Genus GERRES Cuvier. 



MOJARRAS. 



KEY TO SPECIES. 



a\ Preorbital entire ; uo distinct darlv streaks along the rows of scales. 



peruvianus, p. 92. 



a'. Preorbital serrate; a distinct dark streak along i"ows of scales on back 



and sides l periclie, p. 93. 



121. GERRES PERUVIANUS Cuvier and Valenciennes. 

 PERICHE. 



Oerres peruvianus Cuvieb and Valenciennes, Hist. Nat. Poiss., vol. 6, 1830, 

 p. 467; Paiti (Payta). northern Peru. — Jordan and Eveemann, Fishes 

 North and Mid. Anier., vol. 2, 1898, p. 1376. — Gilbeet and Staeks, 

 Fishes of Panama Bay, Mem. California Acad. Sci., vol. 4, 1904. p. 

 115. — Stakks, Fishes from Eucador and Peru, Proc. U. S. Nat. Mus., 

 vol. 30, 1906, p. 792. 



One specimen, field No. 1040, 10.5 cm. long from Capon. 



Head 2.8 in head ; depth 1.91 ; eye 3.33 ; snout 3.33 ; maxillary 2.75 ; 

 interorbital 3.33; pectoral 1; ventral 1.33; D. IX, 10; A. Ill, 8; 

 scales 6-36-9 or 10. 



Body short, compressed, rhomboidal, depth about 2 in length; 

 dorsal outline strongly arched; ventral outline straighter; caudal 

 peduncle slender, its depth 2.5 in head: head short and pointed; 

 interorbital broad, concave, equal in width to diameter of eye and 

 length of snout; mouth moderate: maxillary extending to vertical 

 from anterior border of pupil ; preorbital very narrow, without 

 serrations; margin of preopercle with fine, even serrations; pre- 



