438 FISHES OF THE FIRTH OF FORTH. 



months is not so firm or so wholesome as in autumn and 

 winter. The eggs are shed in the early part of the sea- 

 son, and are occasionally found on the shores with the 

 embryo skate enclosed. When about to be excluded from 

 the horny capsule its tail is disproportionately long, end- 

 ing in a sharp point without an apparent rudiment of a 

 fin. It is capable of being preserved alive in a glass ves- 

 sel for a considerable period, the sea-water being daily re- 

 newed. 



That the adult male Thornback has sharp-pointed teeth 

 does not appear a character so constant, as is supposed by 

 some authors, since I have met with three full grown ex- 

 amples, in which the teeth were as blunt as those observed in 

 the female Thornback. One of the specimens now before me, 

 obtained in the Firth of Forth in the month of September, 

 presents the following characters. Length of the whole 

 fish two feet two inches ; transverse diameter of the body 

 twenty-one inches ; anal appendages six inches, extending 

 half-way down the tail ; at near the tip of the broadest part 

 of each pectoral is a row of long reclined spines, about 

 twelve in number, with their point directed towards the 

 dorsal line; also on or near the margins of the pectorals, 

 in a line with the eyes, are several large spines placed in a 

 cluster with their points directed downwards ; teeth blunt, 

 allowing the finger to be passed in either direction over 

 their summits, without the vestige of a point to be felt ; 

 the teeth being as blunt as those observed in the female 

 specimens of the Thornback. 



A variety of the Thornback is said sometimes to occur, 

 having a dorsal fin on the back, and is named by some 

 authors Rata Cuvieri. A specimen is recorded by Dr Neill 

 to have been taken in the Firth of Forth in 1808. 



