PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. aD 
large; caudal fin well developed; under side of tail flattened with a 
blunt medial ridge. 
Under side covered with a fine shagreen, like the skin of a shark, the 
roughnesses being triangular and closely set, depressible backwards ; 
the skin below much as in Rhinobatus, but the prickles higher and 
sharper, the skin much rougher than in the latter genus. 
The branchial region, from the nostrils to the pelvic bones, is entirely 
smooth, except the lower lip, which has a band of close-set prickles. 
A small tract in the middle of the pelvic area is prickly, and most of 
the abdomen proper, back to a point in front of the vent; the anterior 
and outer three-fourths of the pectorals below and about half the ven- 
trals anteriorly and exteriorly also rough, as is the whole snout below, 
in front of the nostrils; whole lower surface of the tail and the surface 
of the fins rough with shagreen. 
Above, the entire surface is covered with close-set stellated prickles 
of different sizes, largest on the base of the pectorals, and smallest about 
the eyes and on the outer edges of the fins. 
Besides these are several stout, bluntish, slightly recurved spines, 
with stellate bases, placed as follows: One at the upper anterior angle 
of the eye and two behind it, the posterior the larger; a large spine on 
the back at the shoulder-girdle, in front of which are two or three on 
the median line, and a series on the middle line of the back of 10 to 12; 
two more on the tail between the dorsal fins; two series on the shoulder- 
girdle, the inner of two, the outer of two to four. No other large spines 
on the body. No claw-like spines are present on the pectorals in the 
male examples seen, all of which are, however, immature. 
Measurements. 
Piel elenmihene peste se cietaecs a= ose line cfciaaoecnasmeseee-p Oo Aamches, 
Length of disk, to root of ventral..........--.....--.----. 4.4 inches= .51 of total. 
Breadth of disk. :....¢2..- SoSoco cedeo0s GoScno She coasns SSeS See ee ol fe 
Mera NO iM a eet eio ile haievnn Sepals ion lo wie aisle ew ajeisise a Salajsnie semi ete se oie AD ime £° 
SEO WUMLO ISG) PULAINS DIM Ore mentee witiciciceisl since So jeis@iter ane aioe aneetoaiseyeecic ae NUON 
TINT E is 0k. CSC ESBS Gt SOS RR ELS BOSE a ee es See rs ese ae eh ene Se eae 05 fe 
nL OU eM, noe ee Soe seas Seco cmneleh eee) aGaaceciecoeseswisee All! “s 
NKETIE DUA ES DAC Om ee saree ainck clemwicoetcicjseeiacaeame rcoscsien Stes acoeuece WOSD- 1 
PEDO as iM Cu Ominsh CORSA to ac = anna) ceeiseeeis ei seicis jacana miewicis ice = :3l ee 
Length. of first dorsal.....--..-.--- Saeec TRS e HES CBROG Se SOU a ae Oe eeneS 045“ 
See OM RAO OLN =2 5. (an ace cas oh Seaee nen o-assmicieeenes eons seo AU 
ite PAU EUWee UK OLSAIS ase ese seems sen seatse = cisieccitcewecanceseeces Ona, 8 
En Mnee Ct aurin: DELOW ue. 2 22's aemicieee svete ShGiesme es-ce< ese she On 
SiGe MMDetwiceUMOStil so 22c he oe see eeee ee soles occ sisatincisntecee gems 2 ee 
On shia eer OU bers eye mens Saoe en ee eee Se Ee el os et | OO: | 6 
SSLMATEER 12D. ASTON S S56 5 GR apace Ses O OER CCE ae ae ie iene eat at ae ee ae RI: U6 se 
NEO DLaAme hilculancaess aes see meee Se ae osc oe eet ele. 9.995 
Length of branchial _LISDEY Sas a to) ee A a J08D) ite 
This species is very abundant in the Bay of San Diego, where about 
twenty examples of both sexes, all very similar in size, were obtained. 
This. species of the Asiatic genus Platyrhina in the waters of the 
United States is a very interesting addition to our fauna. 
Proc. Nat. Mus. May 6G, i880. 
