60 PROCEEDINGS OF THE ACADEMY OF [April, 



Galeorhinus zyopterus Jordan and Gilbert. 



(Bull. U. S. Nat. Mus., XVI, 1883, p. 871, eiddently based on G. galeus 

 Jordan and Gilbert, Proc. U. S. Nat. Mus., Ill, 1880, p. 42, San Pedro, 

 California; Jordan and Gilbert, I.e., p. 458, San Francisco, Cal.) 



Head 5y; depth 11?; width of head If in its length; depth of head at 

 posterior margin of eye about 2|; snout 2^; eye 4^; width of mouth at 

 corners 2 J ; interorbital space 21- ; front margin of first dorsal 2 ; of second 

 dorsal about 2; of lower caudal lobe If; least depth of caudal peduncle 

 5; upper margin of pectoral 1^; front margin of ventral about 5. 



Body elongate, slender, depressed anteriorly and tapering back 

 from head. Down middle of back, also middle of postventral and 

 postanal regions, a longitudinal groove. Caudal peduncle slender, 

 its least depth about 2^ in its length. 



Head broadly depressed, about equally so above and below, and as 

 viewed from above profile rather elongately convergent with rounded 

 tip. Snout well depressed, its edge but slightly trenchant, and space 

 between its own tip and front of mouth equal to width of latter. Eye 

 large, elongate, lateral and its center falling a trifle posterior in length 

 ■of head. Nictitating membrane large, well developed, and with a deep 

 pocket between itself and eye. Rami of mandible would nearly form 

 a right angle, though symphysis not quite extended forward till opposite 

 front rim of eye. Teeth pointed, mostly tricuspid, and directed to- 

 wards side of mouth, with outer cusp of each of lateral teeth best 

 developed. About 44? series of teeth in upper jaw. Buccal folds 

 rather well developed and papillose. Tongue large, broad, flattened, 

 rounded in front, and its edge free. Nostrils rather large, well separ- 

 ated or internasal space about half width of mouth, each with a small 

 fleshy point, and placed about last f in snout measured to front of eye. 

 Interorbital space broad, a little convex, and depressed medianly. 



Gill-openings 5, last 2 over base of pectoral, and third and fourth 

 largest or about If in eye horizontally. 



Body covered ever5r^'here with simple shagreen points of moderately 

 small and uniform size. 



Origin of first dorsal a Httle nearer that of second than tip of snout, 

 forming a rather rounded lobe with its apex just before posterior basal 

 margin of fin, and point of latter equals eye horizontally. Origin of 

 second dorsal nearer that of first than end of last caudal vertebra by a 

 space equal to width between outer edges of nostrils, apex of fin form- 

 ing about over middle of its length, and its posterior point about IJ 

 in eye horizontally. Origin of anal a trifle after that of second dorsal, 

 its apex forming about first third in its length and its posterior point 

 1} in eye horizontally. Origin of lower caudal lobe a little in advance 



