CLASS PISCES. 613 



tail. It is the species which attains the greatest 

 dimensions. Some have been seen which weigh more 

 than two hundred pounds. It is spotted in its youth, 

 but assumes with age a paler and more uniform tint \ 

 In some species of rays, individuals have been 

 observed, which have upon the middle of the disk 

 a membrane raised in the form of a fin. Such was 

 in the species R. aspera, the Rate Cuvier, Lac. I. 

 vii. 1. I have also seen this in the species clavata. 



Pastinaca, Trygon, Adans 2 ., 



Are recognised by their tail, armed with a prickle 

 dentated like a saw, on both sides, and also by their 

 teeth, all slender, and crowded in a quincunx form. 



1 Add the Rate ondee (R. undulata), Lacep. IV. xiv. 2., which 

 differs little or nothing from the Mosa'ique, Id. lb. xvi. 2 ; the R. 

 chardon (R. fullonica, L.), Rondel. 356. represented under the name 

 of Oxyrhinchus, Bl. 80., and Lacep. I. vi. 1 ; the R. rudula, 

 Laroche, Ann. Mus. XIII. 321. is very much approaching it. The 

 R. lentillat (R. oxyrhinchus), Rondel. 347. of which the Rate 

 bordee, Lacep. V. xx. 2, or the R. rostellata, Risso, pi. i. and ii. 

 Lceviraia, Salv. 142. is a very neighbouring species. R. asterias, 

 Rondel. 350., and Laroche, Ann. Mus. XIII. pi. xx. f. 13. R. 

 miraletus, Rondel. 349. R. aspera, Rondel. 356. 



Remark, that no regard must be paid to the synonymy given by 

 Artedi, Linnaeus, and Bloch, for it is in the most complete confusion, 

 which principally arises from their having employed as the chief 

 character the number of ranges of prickles to the tail, which varies 

 according to age and sex, and cannot serve to distinguish the species. 

 The character of sharp or blunt teeth is not much better, and is often 

 doubtful in its application. 



9 Pastinaca, Tpvywv, or turtle, ancient names of this fish. 



