612 ORDER CHONDROPTERYGII. 



Raia, Cuv., (properly so called), 



Have the disk of a rhomboidal form, the tail tbin, 

 furnished above, towards its point, with two small 

 dorsals, and sometimes with a vestige of a caudal. 

 The teeth are slight, and crowded in a quincunx form 

 on the jaws. Our seas furnish several species, as yet 

 but ill-determined by naturalists. Their flesh is eat- 

 able, though naturally hard and requiring much cook- 

 ing to make it tender. 



Raia clavata, (thornback) L., the male ; Bl. 84. 

 under the name of rubus, the female. One of the 

 most esteemed, is distinguished by its roughness, and 

 by the thick osseous oval tubercles, each furnished 

 with a curved prickle, which irregularly bristle its two 

 surfaces. Their number is very variable. 



R. rubus, L. Lacep. I. v. (rough ray.) Differ from 

 the preceding, by the absence of their thick tubercles. 

 Both have, moreover, some crooked prickles on the 

 front and angle of the fins in the male, and on their 

 posterior edge in the female. The appendages of 

 their males are very long and very complicated \ 



R.batis, L. ; R. oxyrhincus major, Rondel. 348. (the 

 skate.) Has the upper part of the body rough, but 

 without prickles, and a single range of prickles on the 



1 N.B. The Raia batis, Penn. Brit. Zool. No. 30. is nothing but 

 this rubus, Lacep. The rubus of Bl. 84., which is the R. clavata 

 of Will., is, if not a species, at least a variety, remarkable for some 

 scattered tubercles above and underneath. There is also a marked 

 variety, with an eye upon each wing. It is the R. oculata aspera, 

 Rondel. 351. 



