34 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



RHINOBATIDiE. 



53. Rhinobatus productus Ayres. 

 Very common. 



GALEORHINID^. 



54. Mustelus californicus Gill. 



x\buiidaiit. This species appears to be identical with the Atlantic 

 Mustelus canis, itself iutlistingiiishable from Mustelus hinnulus Blainville, 

 of the Mediterranean. 



55. Triacis semifasciatus Grd. 

 ]^ot uncommon. 



56. Galeocerdo sp ? 



The jaAvs of a large shark, with the teeth similar in both jaws, triangu- 

 lar, oblique, deeply notched on the outer margin, and all strongly ser- 

 rate, are preserved by Mr. Pitcher, of San Diego. The shark was taken 

 near San Diego, but south of the Mexican line. The width of the 

 mouth is about a foot. I suppose this to have been a species of Gale- 

 ocerdo. 



HETERODONTID^. 



57. Heterodontus francisci (Grd.) Jor. & Gilb. 

 Common. 



»ESCRIPTION OF A NJEW Fr<OUrV»ER (XYSTKEURVS l-IOIiEPIS). 

 FBOiri SANTA €ATII.flIVA ISL.A1VI>, CAL,IFORI>IA. 



By ©AVID S. JOKa>AM and CHARI.ES II. OILBERT. 



XYSTEEURYS LIOLEPIS, gen. et sp. nov. 



Generic chakacters. — Subfamily Hippoglossinw, allied to Hippo- 

 ;glossina, Rippoglossoides^ and Paraliclithys {Pseudorhomhus). Eyes and 

 color on the right side ; mouth large, oblique, with the teeth developed 

 on both sides, stout, unequal, bluntish, in a single series ; gill-rakers few, 

 short, thick, almost triangular; scales small, cycloid, membraneous, ob- 

 long in form; lateral line simj)le, arched over the pectorals ji caudal fin 

 double-truncate, the angles rounded ; dorsal fin beginning over the eye ; 

 anal fin preceded by a feeble antrorse spine ; ventrals lateral ; body ob- 

 long, moderately deep, rather thin. 



This genus differs from Hippoglossoides in the arched lateral line, and 

 from Ilippoglossina in the cycloid scales and in its dextral habit. From 

 jnost of the related genera it is separated by the few stout short gill ■ 

 rakers. 



