22 SELACmi: RAIyK. — V. 



21. TORPEDO Diimoril. 



30. T. occidentalis Storer. 'J'oki'kdo. Ckamp-fish. Numb- 

 fish. Black, with obscure darker blotehe.s; spiracles with eutire 

 edges. L. 3 to 5 feet. Cape Cod S. ; not common. 



Family XVI. DASYATID^. ('Iiii; STiNci-HAYs.) 



Disk broad, the peotoral.-^ coiitliient anteriorly, formin;; ti[) of 

 snout; tail, usually wlii]>-liki', sonictiincs short and stout, •vvi'.h or 

 without (ins, but never with two dorsals. Tail usually armed with 

 a sharp, retrorsely serrate spine above, near the base (this often 

 duplicated and sometimes wanting;) : ventral fins entire. Sliin 

 smooth or variously rough, the adult roughest. !Mouth small, with 

 small teeth. Se.xes similar, (ienera 10, species 50, in most 

 warm seas. The large si)ine or " sting " on the tail in most species 

 may inflict a dangerous wound. 



a. Tail sk-iukT, whip-like, without caudal I'm, lcin;;(>r than tho disk; "stinp" 



on tail strong Dasyatis, 22. 



aa. Tail very slender and short, shorter than the very liroad disk : sting 

 minute or wanting I'TKiiorLATEA, 23. 



22. DASYATIS Rafinesque. (Tn/gon Adanson.) 

 (Siio-ilv, shaggy or rough ; /Sartr, skate.) 

 a. Tail with a fold on its lower margin only, the upper edge rounded. 



31. D. centrurus (Mitchill). Com.mox Sti.\<;-Ray. Clam- 

 CuACKKU. Stincakkk. Snout not prominent; disk a little wider 

 than long; tail usually not (juite twice length of disk. Adult 

 with some stellate tubercles on back and tail. Color olive-browu. 

 L. 12 feet. Cape Cod S., common. (Kfurpov. spine; ovpa, tail.) 

 aa. Tail with a (bid of skin on its upper as well a.s lower margin. 



32. D. say (Le Sueur). Sol'TIIFUN Stixc.-Ray. Wiiii'- 

 PAKEE. Snout not prominent; disk a little wider than long; tail 

 nearly twice length of disk. Body and tail without large sjiines. 

 N. Y., S. (To Thomas Say, a distinguished zoologist.) 



23. PTEROPLATEA, Miiller & Ilcnie. 

 3.'}. P. maclura(Le Sueur). Butterfly Ray. Disk nearly 

 twice as broad as long, three times as long as tail ; sting on tail 

 usually obsolete. Olive-brown, finely marbled and si)eckled ; tail 

 with four dark blotdies : front ed^'e of disk with pale halfi-ircular 

 spots. Va. S. (To William Madure.) 



Family XVII. AETOBATID^. (The Eau.le Ray.s.) 

 Pectoral fins inti-rrupted, reanpearing on tip of snout as one or 

 two detached appendages or <'ephali<' (ins ; skull somewhat elevated, 

 so that eyes anil .<pirac"les arc lateral : teeth large, (lat, he.xangular, 



