NO. 1824. ELASMOBRANCHTATE FISHI^S— JORDAN ANT) FOWLER. 657 



Jsmall, paved, usually more or less pointed or tubercular. Nostrils 



I close together; nasal valves forming a roctanoular Hap, which is joined 

 to the upper jaw by a narrow f renum. Spiracles large, placed close 

 behind the eyes. Skull not elevated, the eyes and spiracles superior. 

 Species ovoviviparous. Found in most warm seas, some of them in 

 the fresh waters of the northern i)arts of South America. 'Vlw lar<>-e 



I jagged spine on the muscular tail is capable of inllicting a severe and 



[even dangerous wound. 



a. Frolophin.k. Tail stout, provided wit! i a rayed caudal liu; nodunsal fin; disk 



rouudish ; caudal spine strong UrolopJiux, 39. 



u(i. Dasyatin.e. Tail slender, without caudal lin; jielvis without swoi-d-shapcil 

 process. (Marine species. ) 

 b. Tail whiplike, longer than disk, which is rhomboid, or roundish; caudal spine 



strong Dasynlis, 40. 



bb. Tail very short, shorter than the very broad, transversely rhond)ic disk; caudal 

 spine weak, often wanting; no trace of dorsal fin Pteroplated, 41. 



39. UROLOPHUS Mlillep and Henle. 



Lfiubalm" Blainville, Jour. Phys., LXXXIII, 1816, j). 262 {crurifttus; not 



LelobaiH.^, Rafinesque, 1810). 

 Leiobatlf< Blainville, Faune Fran^aise, 1828, p. 4'A (no type named). 

 Uroloplmii MtiLLER and Henle, Plagiostomen, 1838, p. 17S {uurantiaeux=criiriaiu.'<) . 

 Urotnjgoii Gill, Proc. Ac. Nat. 8ci. Phila., 1863, p. 173 {mimdns). 



Disk oval or rhom))ic, the length and breadth not very unequal; 

 snout rounded or the tip exserted; skin smooth or more or less prickly. 

 Tail rather short, little if an}- longer than the disk, muscular, provided 

 with a distinct rayed caudal tin; no dor.sal lin. Upper part of the tail 

 with a strong, serrated spine. Warm seas. Sting rays of small size, 

 the most vigorous and most dangerous of the group, mostly contined 

 to tropical America. 



{ovpd, tail; Ao^og, crest.) 



46. UROLOPHUS FUSCUS Garman. 

 JUNORUI. 



Urolophus fuscu.'i Garman, Proc. U. S. Nat. Mus., 1885, p. 41; East Coast of Japan 



(Type No. 7058, U. S. Nat. Mus.). 

 Trnlnphna ln/lbrriji Nystrom, Kongl. Svensk. Vet. Akad., 1887, p. 53; Nagasaki 



(C(j11. Dr. W. Tulll)erg).— Jordan and Snyder, Proc. U. S. Nat. Mus., 1900, 



p. 338; Tokyo. 



Disk round, angles of pectorals about opposite tirst two-hfths its 

 length. Head small, snout produced only in a short point; anterior 

 edge of disk broadly convex; eyes rather small, 5 in snout and H i» 

 interorbital space; nostrils large, confluent with mouth only separated 

 in middle by a thick frenum; mouth small, H in interorbital space; 



" In the Faune FranQaise, 1828, Blainville changes "batus" in this and all similar 

 names to "fta//.s," thus Leinbufis, Ai'tobnih. In this form the name Lriobdti.'^ has pri- 

 ority over UroIophuK, l)ut being not a new name, but a mere variant in spelling, it is 

 perhaps not necessary to adopt it as the name of this genus. 



