PEARLED RAY. 28Q 



times two spines are found instead of one : back, 

 from between the eyes to some distance beyond 

 the base of the tail, covered with pretty close-set 

 tubercles or granules, three of which, in the middle 

 of the back, are far larger than the rest, and re- 

 semble three pearls disposed in a longitudinal di- 

 rection on that part : colour of the whole animal 

 deep cinereous brown above, and reddish white 

 beneath : grows to a large size, sometimes measur- 

 ing eleven feet from the snout to the end of the 

 tail. Native of the Red Sea. 



It is from the skin of this species, according to 

 Cepede, that the beautiful substance called Galu- 

 chat by the French is prepared, and which being 

 coloured with blue, green, or red, according to the 

 fancy of the artist, and afterwards polished, is so 

 frequently used for various kinds of cases, telescope- 

 tubes, &c. &c. For this purpose the smaller or 

 younger specimens are preferred; the tubercles 

 in the more advanced or full-grown animals being 

 too large for the uses above-mentioned. , 



* Var, 



Wolga Tenkee. Russ. pise. ind. t, 3. 



This seems to be a variety of the preceding : 

 the length of the specimen described by Dr. Russel 

 w^as about nine inches and a half, the tail about 

 two feet nine inches : colour of the whole animal 

 dull leaden above, with deep-blue tail: beneath 

 dusky white : on the middle of the back only two 



