PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 53 

 ON THE GENEKIC RELATIONS OF PliATTKHBNA EXASPERATA. 



By DAVID S. JORDAN and CHARLES II. GILBERT. 



A short time siuce a small ray was described by the present writers, 

 from San Die.c^o, under the name of Platyrhina exas])erata. (Proc. U. S. 



Nat. Mns. 1880, .) Soon after a second species was described by ns, 



from Santa Barbara, as PlatyrJiina triseriata. (Proc. U. S. Nat. Mus. 

 1880, .) 



The two species are certainly not congeneric. The former species has 

 the skin above covered with stellated prickles of difierent sizes, and re- 

 sembles the genus Eaia. The latter is covered over by a uniform line 

 shagreen, and resembles the species of syrrMna and rliinohatus. So far 

 as we can ascertain from the description given by Dumdril and Giinther 

 of Platyrhina sinensis and Platyrhina schcenleini, these two species agree 

 with Platyrhina triseriata in the character of the dermal covering, as well 

 as in form of body. We propose therefore to consider Platyrhina exas- 

 perata as the type of a distinct genus, Zapteryx, distinguished from Pla- 

 tyrhina by the presence of detached, unequal, stellated prickles on the 

 skin above, instead of the uniform shagreen covering found in Platyrhina, 

 and from Eaiahj the convex outline of the ventrals and by the greater 

 development of the dorsal and caudal fins. In Baia the ventrals are 

 always emarginate. 



March 26, 1880. 



RE^TIARKS ON THE SPECIES OF THE OENUS CHIRITS FOUND IN 

 SAN FRANCISCO MARKET, INCEIJHING ONE HITHERTO UNDE- 

 SCRIBEO. 



By W. W. tOCKINGTOX. 



Four species of the genus Chirus occur in the markets of this city. 

 The two most abundant of these are C. constellatus and C. guttatiis 

 Grd. Of the others, one is C. pictus Grd., while the other has until 

 now remained undescribed. 



C. pictus is separated from the others by some sufficiently obvious 

 external characters, beside those of color, as will be evident from the 

 subsequent remarks, but the writer is unable to find any constant char- 

 acter except that of the coloration by which to distinguish the other 

 three species. 



As, however, he has now seen several hundred examj)les of C. guttatus 

 and C. constellatus, and a large number of both the other species, and 

 as, notwithstanding the considerable variation in the size, number, and 

 position of the marking of each species, neither on any occasion shows 

 the slightest tendency to approach the pattern of another, he submits 

 that in this group the pattern of the coloration may be considered 

 specific. 



