FISHES OF WEST COAST OF PERU. 131 



Genus BALISTES (Artedi) Linnaeus. 



155. BALISTES POLYLEPIS Steindachner. 



PEJE-CHANCHO. 



Plate 12, fig. 2. 



Batistes polylepis Steindachner, Ichth, Beitr., vol. 5, 1876, p. 21, Magda- 

 lena Bay; Mazatlan; Acapulco. — Jordan and Evermann, Fishes North 

 and Mid. Amer., vol. 2, 1898, p. 1900. — Gilbert and Starks, Fishes of 

 Panama Bay, Mem. California Acad. Sci., vol. 4, 1904, p. 152. 



One specimen, field No. 09472, 45 cm. long, from Lobos de Afuera, 

 taken by fishermen in about 25 fathoms. 



Head to lower end of gill slit 3.4 in length; depth 1.8; eye 5.2; 

 snout 1.25; interorbital 2.5; pectoral 2; first dorsal spine 1.44; long- 

 est dorsal ray 1.13 ; longest anal ray 1.35 ; upper caudal ray longest, 

 0.95; D. III-26; A. 24; oblique rows of scales, counted downward 

 and backward, 65, counted downward and forward, 75 ; scales from 

 origin of dorsal to anal origin, 60 ; preocular groove prominent. 



Body short and deep, dorsal and ventral outlines strongly arched ; 

 caudal peduncle slender, unarmed, its least depth 3.5 in head ; upper 

 profile of head very slightly convex; eye small, high, within 1^ 

 diameters of origin of dorsal; eight strong teeth in each jaw; a 

 strong groove in front of eye, its length greater than diameter of 

 eye ; plates behind gill-opening large ; dorsal fin high, falcate ; outer 

 rays of caudal greatly produced, fin concave; anal triangular, ante- 

 rior rays longest; pectorals small. 



Color in alcohol, olive brown, darkest on back ; fins dusky. 



This species differs from B. naufraglum in having 64 rows of 

 scales counted downward and backward instead of 46 to 50; in 

 having the preocular groove much more prominent; the small 

 tubercle on scales less prominent; the dorsal more falcate; the 

 caudal lobes longer ; the middle rays less produced ; and the colora- 

 tion plainer. 



Specimens from Guadalupe Island, Mazatlan, and Panama Bay 

 have 27 or 28 dorsal and 25 or 26 anal rays. Gilbert and Starks 

 state that the lower caudal lobe is shorter in the specimens from 

 Panama ; in our specimen the opposite is true. 



Genus CANTHIDERMIS Swainson. 



156. CANTHroERMIS ADSPERSUS (Tschudi). 



Balistes adspersns Tschudi, Fauna Peruana, Ichth., 1845, p. 31 ; Huacho. — • 



Abbott, Marine Fishes of Peru, Proc. Acad. Nat. Sci. Phila., 1899, p. 360. 



fCanthidermis angiilosus Snodgrass and B^ller, Shore Fishes Galapagos 



Islands, Proc. Washington Acad. Sci., vol. 6, 1905, p. 407. 



Canthidermis angulosus Kendall and Radcliffe, Shore Fishes, Agassiz- 



Alhatross Eastern Pacific Expedition, Mem. Mus. Comp. Zool., vol. 35, 



No. 8, April, 1912, p. 164. 



In Shore Fishes of the Galapagos Island (p. 407), Snodgrass and 



Heller describe a large example of C. angulosus from Cocos Island 



