OF THE CRAB TRIBE. 549 



species, is armed with a hard, pointed, and crooked sting, the poison 

 of 'vhich is very powerful. 



In some parts of Italy and France these animals are among the 

 greatest pests that can plague mankind ; but in those countries of the 

 East, where they grow to a foot in length, there is no removing a 

 piece of furniture, without danger of being stung by them. There, 

 we are told, they are nearly as large as small Lobsters. 



Many experiments have been made to ascertain the strength of tLeii 

 poison ; and, in warm climates, it has uniformly been found fatal to 

 small animals. To man the wound is extremely painful. The place 

 becomes inflamed, and the surrounding parts often turn livid, and re- 

 quire to be carefully dressed in order to prevent mortification. 



OF- THE CRAB TRIBE. 



ALL the animals of this tribe have their bodies covered with a hard 

 and strong shell. The head is united to the thorax or breast without 

 any joint. 



These animals live chiefly in the sea ; some, however, inhabit the 

 fresh waters, and a few live on land. They feed variously, on aquatic 

 or marine plants, small fish, molluscae, or dead bodies. The females 

 carry their ova under their tail, which, for that purpose, is in general, 

 much broader than that of the males. 



The animals emphatically denominated Crabs, have a short, flat tail, 

 bent close to the body in a hollow between the legs. The Hermit-crabs 

 have a soft tail, without any crustaceous covering : this they fit into 

 empty shells, or hollow stones. In the Lobsters the tail is the princi- 

 pal part of the body, being a very strong member, and employed with 

 great advantage both in swimming and leaping. This is formed of 

 six convex segments, which lie over each other, somewhat like the tiles 

 of a house, and are terminated by five laminae, or thin plates. The 

 former are united by loose membranes, which admit of much motion. 

 At the angle where the upper and lower parts join, these segments are 

 furnished with a kind of crustaceous fins, bordered with hair, and 

 consisting of several articulations, called by naturalists pedes natatorii. 

 The fins are moved, backward and forward, and a little outward and 

 inward, by small muscles, contained within each articulation. By 

 means of these it is that the animals have their progressive motion 

 at different depths in the water. 



Most of the Crabs have eight legs, (a few, however, have six, or ten,) 

 besides two large claws, which serve the purposes of hands. They 

 have two eyes, situated on tubercles projecting from the head, and 

 movable in any direction. When the extremities of these are viewed 

 with a glass, they are found to be composed of a multitude of lenses, 

 like the eyes of insects. For a sense of touch, these animals are fur- 

 nished with antennae, and palpi, or feelers. They have likewise a 

 heart, with arterial and venous vessels, and branchiae or gills for re- 

 spiration. Their jaws are transverse, strong, and numerous ; and the 

 stomach is furnished with internal teeth. 



