142 CLASS CRUSTACEA, 



" The fish whose mouth he inhabits, comes about the 

 same time with the shad into the rivers of Virginia from 

 the ocean, and continues to travel upwards from the 

 beginning of March to the middle of May. As long as 

 they are caught on their passage up the river, they are 

 found fat and fall of roe. Every fish which I saw had 

 the Oniscus in his mouth, and I was assurred, not only 

 by the more ignorant fishermen, but by a very intelligent 

 man who came down now and then to divert himself 

 with fishing, that in forty years' observation he had 

 never seen aBay Alewife without the louse." 



The Oniscus itself, as the author states, is not without 

 its enemies, many of them being caught with two or 

 three leeches attached to their body, and adhering so 

 closely that their removal cost them their heads. 



The Molucca Crab, {Folypliemus gigas.) 



Why the singular creature here represented should have 

 the name Polyphemus given to it, is hard to guess. 

 Polyphemus, as every school-boy knows, was the fabled 

 giant overcome by Ulysses, who is represented as having 

 one eye in the centre of his forehead; whereas, this 

 creature has two eyes and one horn. It is interesting 

 from its being so nearly allied to many very minute 

 species. 



The Polyphemus sometimes reaches the length of two 

 feet; there are but two species, which only differ from 

 each other in the shape of their buckler. That we have 

 represented is found in the Indian Ocean, and has been 

 called the Molucca Crab. 



The tail, or rather the horn, of the Polyphemus, is 

 greatly dreaded by the fishermen, from the idea that its 

 wound is venomous. The natives employ it to point 



