32 BULLETIN 189, UNITP^D STATES NATIONAL MUSEUM 



conclusion that M. abbotti is a synonym of M. mento. Fowler (1908, 

 p. 57), who redescribed the type of M. mento, did not follow 

 Bigelow and Schroeder in his list of fishes of Peru (1941a, p. 222) 

 wherein he recognized M. mento, but placed M. abbotti in the synonymy 

 of M. dorsalis. Although I have not seen the type of M. mento, 

 Fowler's description and figure (1908, p. 57, fig, 1) of the type make 

 it possible to state definitely that M. mento is not identical with M. 

 dorsalis, because the type of M. mento, which according to Cope 

 is only 303 mm. long, still retains dark cross bars on the anterior 

 part of the body, which M. dorsalis never possesses, as shown in the 

 account of the last-mentioned species. Furthermore, the published 

 accounts, as well as Fowler's figure give no character for separating 

 M. abbotti and M. mento. The writer, therefore, has arrived at the 

 conclusion with Bigelow and Schroeder (loc. cit.) that the two are 

 identical. 



The species is represented in the collection by sjix adult specimens, 

 555 to 700 mm. long, and by seven embryos, all removed from one fe- 

 male, and all around 210 mm. long. Five of the larger specimens, con- 

 sisting of three males and two females, were taken with hook and line 

 at San Lorenzo Island, near Callao, and one female, also caught with 

 hook and line, on the south side of La Punta, Callao. The female 

 from which the embryos were removed was taken on a line trawl in 

 9 to 10 fathoms off Lobos de Tierra Island on August 17. A length 

 of at least 120 cm. is attained, as the female with embryos, already 

 mentioned, had reached that length. Mr. LobeU of the Mission re- 

 marked in his field notes, "This species of shark is extensively used for 

 food, both fresh and salted and dried in the sun." The dried product 

 appears to be called bacalao. 



Range. — Coast of Peru and apparently southward about to Con- 

 cepcion, Chile. 



MUSTELUS DORSALIS Gfll 



TOLLO 



Figure 6 



Mustelus dorsalis Gill, 1864, p. 149, Panama Bay (original description). — 

 EvERMANN and Radcliffe, 1917, p. 7, pi. 1, fig. 3; pi. 2, fig. 1, Pacasmayo, 

 and Lobos de Tierra, Peru. — Nichols and Murphy, 1922, p. 504, Callao 

 market, Peru. — Fowler (part), 1941a, p. 222 (references). — Beebe and Tee- 

 Van, 1941, p. 103, fig. 11 (range, field characters; size; references). 



Depth at origin of first dorsal 7.2 to 8.3 in length anterior to base 

 of upper lobe of caudal; head to first giU slit 4.5; length to origin of 

 first dorsal 2.4 to 2.5; distance between dorsal fins 4.0 to 4.4; upper 

 lobe of caudal 4.0 to 4.3 ; greatest length of pectoral 5.4 to 5.6. Snout 

 2.3 in head to first gill slit, its preoral^ length 2.9 to 3.0; width of 

 mouth at angles 3.1 ; eye 6.8 to 6.9; caudal peduncle 7.2; base of anal 

 3.4; outer margin of ventral 2.4. 



