PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 53 
ON THE GENERIC RELATIONS OF PLATYREINA EXASPERATA. 
By DAVID S. JORDAN and CHARLES H. GILBERT. 
A short time since a small ray was described by the present writers, 
from San Diego, under the name of Platyrhina exasperata. (Proc. U.S. 
Nat. Mus. 1880, ——.) Soon after a second species was described by us, 
from Santa Barbara, as Platyrhina triseriata. (Proce. U.S. Nat. Mus. 
1880, ——.) 
The two species are certainly not congeneric. The former species has 
the skin above covered with stellated prickles of different sizes, and re- 
sembles the genus Raia. The latter is covered over by a uniform fine 
shagreen, and resembles the species of syrrhina and rhinobatus. So far 
as we can ascertain from the description given by Duméril and Giinther 
of Platyrhina sinensis and Platyrhina schenleini, 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 Raia by the convex outline of the ventrals and by the greater 
development of the dorsal and caudal fins. In Raia the ventrals are 
always emarginate. 
MARCH 26, 1880. 
REMARKS ON THE SPECIES OF THE GENUS CHIRUS FOUND IN 
SAN FRANCISCO MARKET, INCLUDING ONE HITHERTO UNDE. 
SCRIBED. 
By W. N. LOCKINGTON. 
Four species of the genus Chirus occur in the markets of this city. 
The two most abundant of these are C. constellatus and C. guttatus 
Grd. Of the others, one is OC. 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 examples 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. 
