Tfc'E THORNBACK, 
EI-3 
The Ihornlaek *. 
1 he thornback is the la ft of this genus which we ihali 
Particularife ; and its figure is fo well known, that a Ikort 
defcription will fuffice. It is of a rhomboidal fhape, 
broader, however, than long, and diftinguilhed from all 
the other fpecies of the ray, by three rows of fpines upon 
the back, and five upon the tail, all pointing towards its 
end. The mouth is fmall, and fitted with granulated 
teeth ; between the nofe and the eyes are a few r fpines ; o- 
thers are fcattered without any order upon the pe&cral 
fins. 
The colour of the upper part of the body is that of 
Pale allies, marked with llreaks of black, and the ikm 
r °ugh, with fmall tubercles like ihagreen. The belly is 
^hite, eroded with a ftrong femilunar cartilage f. Wil- 
Tughhy has given a long detail of the internal ftmcture 
this fpecies ; by which it appears, that it has two di- 
fi‘n£t organs, of a curious conformation, one on each fide, 
r ° r generating and excluding its eggs : In thefe are depo- 
’ tcd enumerable ova of various fiz.es J; hence, the thorn- 
a ck muft be very prolific. It begins to generate in the 
eenth of June, and continues produclion till September ; 
Us young, as long they are incapable of breeding, are 
a 'kd maids ; they are good eating at all times of the 
y ar, but the old only begin to be in feafon in the month 
oi November. 
VoL - NI. P Xhe 
\ c ' avata . Lirt. Syft. Idem Rondeletii et Will, 
t^WiZoa. i Ichthyol. p, 76, 
