90 



mermaid's purses. 



to the shark's head is formed so as to open by 

 the slightest pressure from within. After the 

 newlj-born shark has left the egg-shell, there is 

 no perceptible external change in its shape, for 

 the sides are elastic, and immediately close up as 

 before. 



These eggs are popularly known by the poetical 

 title of Mermaid's Purses — alas, empty ! 



There is another and more common Mermaid's 

 Purse, that is found of various sizes and of 

 various tints, although it is usually of a very 

 dark brown, closely approximating to black, and 

 in length from three to five inches. It will be 

 at once recognised by the figure on plate h fig. 1. 



This egg is the production of one of the skates, 

 and harmonises well with the strange, weird-like 

 aspect of the creature from which it was pro- 

 duced. The accompanying figure represents the 

 Thornback Skate {Raia clavata), a species that 

 often attains a very great size, measuring some 

 ten or eleven feet in length, and very nearly as 

 much in breadth. From the four short arms 

 with which these eggs are furnished, they are 

 thought to bear some resemblance to hand- 

 barrows ; and if a fisherman is asked the name 

 of the object, he will generally call it " Skate- 

 barrer." If the egg is picked up in the early 



