144 CLASS CRUSTACEA. 



The Crab-like Limulus, {LimuTus cancriformis.) 



The Limuli are found in deep ditches of fresh water, 

 marshes, &c, ; they are frequently met with congregated 

 together in great numbers ; their principal food in the 

 Spring appears to be tadpoles. 



' Limulus cancriformis. (Natural size.) 



" Tliis genus," says Lamarck, " is almost isolated 

 among the group in which it is placed. Its body is 

 covered with a great horny buckler, very thin, and made 

 of a single piece, of a roundish oval form. The head is 

 confounded with the trunk, and the antennse are very 

 short. They possess three eyes, two in front, and one, 

 very small, further back. Their legs are very numerous, 

 — the two in front, much the largest, spread out in the 

 form of oars, and furnished at their extremity with silky 

 articulated bristles." 



The Water Flea, {Cyclops quadricornis.) 



There are as many as twelve known species of the 

 Water Flea. That represented in the engraving is 

 extremely common, and forms a most interesting object 

 for the microscope. We have availed ourselves of 



