46 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY ^IV. 



38.~UKOLOPHUS Mulhn- & Heule. 



Round ^ting Rays. 



(Miiller & Heule, Plagiostoiiieii, 1837, 173 : type Urolophna anrantiacus Miiller & Henle 

 = Raiacrnciata Lac6pede.) 



Disk oval or rhombic, the length and breadth not very unequal. 



Suout rounded or slightly prominent. Skin smooth or somewhat prickly. 



Tail rather short, little if any longer than the disk, muscular, provided 



with a distinct rayed caudal fin ; no dorsal fin. Upper part of the tail 



with a strong serrated spine. Warm seas. Size small, {udftd, tail; 



Aw^oc, crest.) 



* Skill perfectly smooth. 



58. U. Iiallori Cooiier. 



Disk nearly round, a little broader than long, with the anterior mar- 

 gins straightish, meeting in a slight angle. Snout (from the eyes) longer 

 than the width of the interorbital space. Tail somewhat shorter than 

 the disk. Skin without spines or prickles. Color light brownish, with 

 marblings and wavy lines of yellowish and dusky, sometimes with 

 yellowish spots, occasionally with wide, obscnre dusky streaks, which 

 are crossed by similar transverse streaks. Belly yellowish tinged. 

 Coast of California, from Point Concepcion southward ; exceedingly 

 abundant in sheltered bays. L. 12. The smallest of our sting rays. 

 Closely related to the Australian U. cruciatus, if not identical with it. 



(Cooper, Proc. Calif. Ac. Nat. Sci. iii, 95.) 



39.— PTEROP1.ATEA Miiller & Heule. 

 (Miiller & Heule, Plagio.stomeu, 1837, 168: type Eaia altavcia L.) 



Disk much broader than long, its anterior margins meeting in a very 

 obtuse angle, its outer angles more or less acute. Tail very short and 

 slender, shorter than the disk, without fin, usually armed with a small 

 serrated spine. Skin smooth or very nearly so. Size moderate or rather 

 large. Warm seas. (--£/>«, fins; z-Aar^a, broad ; 7rT£pu;:,iar£ ra, an ancient 

 name of P. altavela.) 



*Si)iraele without teutaele. 



59. P. BUa,clura, (Le Sueur) Miiller & Heule. — Butterjiy Bay. 



Disk scarcely twice as broad as long, covered with perfectly smooth 

 skin. Tail about one-third as long as the disk, with a very slight der- 

 mal fold above and below. Snoitt a little projecting, so that the anterior 

 edge of -each pectoral is somewhat concave. Color brownish olive, 

 finely marbled with grayish, and finely speckled. Anterior edge of disk 



