THE SHORE FISHES OF PERU 267 



UMBRINA XANTI Gill 

 POLLA 



Umbrina xanti Gill, 1862, p. 257, Cape San Lucas, Baja California (original 

 description). — Evermann and Radcliffe, 1917, p. 105, Tumbes, Peru 

 (synonymy; description, based on a specimen 280 mm. long). — Meek and 

 HiLDEBRAND, 1925, p. 615, Panama Bay (synonymy; description; range). 



Head 3.6 to 4.0; depth 3.2 to 3.4; D. X-I, 27 to 30; A. II, 6 (rarely 

 5); P. 17 or 18; scales 63 to 70. 



Body oblong, well compressed, its greatest tliickness somewhat less 

 than half its depth; back rather strongly elevated; dorsal profile 

 anteriorly notably convex; head fairly small; caudal peduncle short, 

 rather strongly compressed, 2.5 to 3.1 in head; snout conical, pro- 

 jecting beyond mouth, 3.0 to 3.5; eye 3.7 to 5.8; interorbital 3.6 to 

 4.8; mouth horizontal; lower jaw included, with a short thick barbel 

 at its tip ; maxillary extending nearly or quite to vertical from posterior 

 margin of pupil, 2.8 to 3.1 in head; teeth in a band in each jaw, the 

 outer ones in upper jaw somewhat enlarged; margin of preopercle 

 finely serrate; gill rakers short, better developed in small specimens 

 than in large ones, 7 to 11 more or less developed on lower and 5 to 7 

 on upper limb of first arch; lateral line slightly arched anteriorly, then 

 decurved, reaching middle of side over end of anal base; scales 

 strongly ctenoid, rows irregular, those above lateral line strongly 

 oblique, becoming parallel with lateral line on caudal peduncle only, 

 5 or 6 rows between lateral line and base of first dorsal spine, extending 

 more or less on all the fins, exclusive of spinous dorsal and anal; dorsal 

 fins contiguous in small specimens, rather well separated in large ones, 

 the spines slender, the second and more usually the third longest, 1.6 

 to 1.75 in head, anterior rays of second dorsal longest, margin of fin 

 slightly convex; caudal emarginate, the upper lobe acute, the lower one 

 rounded ; anal very small, the second spine fairly strong, proportion- 

 ately shorter in adult, 2.2 to 3.1 in head; ventral moderate, 1.3 to 

 1.5 in head; pectoral short, not reaching tip of ventral, fourth and 

 fifth rays longest, 1.4 to 1.6 in head, 5.6 to 6.0 in length. 



Color silvery, with conspicuous dark stripes along the rows of scales 

 on back and sides; inside lining of gill covers black, apparently 

 showing through the opercle, as a dark blotch; fins plain, the dorsal 

 fins, caudal, and pectoral slightly dusky. 



This species is represented in the collection furnished by the Mission 

 by 11 specimens, 10 small ones, 95 to 155 mm. (76 to 128 mm. to base 

 of caudal) long, and 1 large one, 465 mm. (390 mm. to base caudal) 

 long, all from Lobos de Tierra Island and Bay. In addition there is 

 at hand a specimen, 75 mm. (62 mm. to base of caudal) long, taken off 

 Paita by W. L. Schmitt; also a specimen reported by Evermann and 

 Radcliffe (see reference above), 280 mm. (235 mm. to base of caudal) 

 long, from Tumbes. The local name "poUa" is given in the work by 



