94 



HALGAN'S SPINE-TAILED RAY. 



Trygon Halgani^ Lesson. 



PLATE V. 



Trygon lymna. — Ruppell, pi. xiii. fig. 1. 



This species of ray, so very distinct froni most of 

 its congeners by the bright spotting which adorn its 

 upper surface, seems to have been known and de- 

 scribed by several travellers, or there may be one or 

 two species which are closely allied by their form and 

 markings ; for the figure of Riippell represents two 

 spines on the tail, whereas Lesson's fish has only one 

 of these organs of defence. It is a small species ; the 

 general size of the species being only about six Inches 

 in length, to which may be added about eight inches 

 for that of the tail ; the spine is placed about the 

 middle of the tail, is flattened at the base, and at the 

 point is finely barbed, which would cause it to inflict 

 a dangerous wound. Tlie upper part of the fish, or 

 back, is thickly marked with azure spots, as we 

 have endeavoured to represent, and which beauti- 

 fully relieves the pale uniform tint which otherwise 

 covers it. Lesson and the expedition met with 

 Halgan s ray very abundant in the Bay of Offkck, 



