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BULLETIN 189, UNITED STATES NATIONAL MUSEUM 



except on the spearlike tip; snout somewhat exserted, pointed, its 

 length anterior to eye 3.9, 3.4 in length anterior to axil of pectoral, 

 its preoral length 3.55, 4.0; interorbital 9.5, 9.6; internarial space 8.2, 

 8.95; eye and spiracle about equal, 3.9, 4.3 in snout; mouth transverse, 

 its width 8.0, 9.5 in length anterior to axil of pectoral; teeth with small 

 sharp cusps; disk smooth except for a patch of prickles on the snout, 

 and some dorsal spines; the larger specimen (type) with an almost 

 continuous median series of spines from nuchal region to caudal 





Figure IS. — Urotrygon peruanus, new species. From the type, 276 mm. long, Paita Bay, 

 Peru (U.S.N.M. No. 127793). Insert, diagram of outline of snout and position of mouth 

 and nostrils. 



spine; the smaller specimen (paratype) with a median series of smaller 

 spines on tail only; ventral very broadly rounded, its outer (lateral) 

 margin 5.4, 5.65 in length anterior to axil of pectoral; claspers short, 

 stout, scarcely as long as the outer margin of ventral. 



Color of the large specimen at hand nearly plain grayish brown above, 

 with few very small scattered dark spots; pale underneath; a smaller 

 specimen more grayish, with rather numerous dark spots; a very small 

 specimen plain gray. 



