44 BULLETIN 189, UNITED STATES NATIONAL MUSEUM 



proportions show that large individuals have proportionately shorter 

 heads and smaller eyes, as expected; that the upper lobe of the caudal 

 is shorter; and that the pectorals become more pointed with age, and 

 also increase in proportionate length. 



It is not evident now from the meager material available for study 

 wherein the Peruvian specimens differ from California examples, 

 which include the small eviscerated "types" (U.S.N.M. No. 26973). 

 Therefore, the Peruvian specimens are here placed with 6. zyopierus, 

 the common and valuable soupfin shark of the Pacific coast of the 

 United States, where they may remain at least until a more thorough 

 study of the Pacific coast residents in comparison with the apparently 

 closely related Atlantic (European) form, G. galeus (Linnaeus), can 

 be made. 



The nine embryos in the collection were removed from a female 148 

 cm. long, taken at Lobos de Afuera Island on July 19. The one from 

 which the head, now at hand, was removed apparently was one of the 

 four females, 152 to 158 cm. long, for which some proportions are 

 given above, which were caught at the same place on July 20. The 

 male, of which the jaws and some of the fins were saved, was taken at 

 Atico Point. The specimens appear to have all been caught with line 

 trawls. In addition to the specimens already mentioned, two small 

 specimens 363 and 384 mm. long (U.S.N.M. Nos. 77542 and 77641), 

 taken at Pacasmayo, also were used in preparing the description. 

 This shark probably is common in Peru. 



Range. — Washington State to southern Peru, and possibly to Chile 

 if Galeus chilensis Perez Canto and Galeus molinae Philippi should 

 prove to be the same. There are as yet no records of the capture of 

 specimens between Baja California and Peru. The absence of speci- 

 mens in collections from intermediate localities suggests the probabil- 

 ity that a comparison of a good series of examples from the two regions 

 where this shark is common might reveal some differences. 



Family CETORHINIDAE: Basking Sharks 



Body massive anteriorly, tapering rather abruptly behind first 

 dorsal fin; head and snout somewhat conical; eye small, lateral, with- 

 out nictitating membrane; spiracle small, in front of eye; mouth 

 large; teeth very small, numerous, conic; gill slits very long, extending 

 from dorsal surface nearly to midline of throat, all in front of pectoral; 

 first dorsal large, about equidistant from pectorals and ventrals; 

 second dorsal and anal small, opposite each other; caudal lunate, upper 

 lobe the longer, with keels near its base; pectoral large. 



A single genus and species has been recognized. Large pelagic 

 sharks. 



