TETRADECAPODA. 645 



Several species of the River Lobster are found in the United 

 States. 



The LOBSTER, Astacus marinus, is very abundant and of great 

 commercial value. Good sized ones are four and a half inches 

 long, from the tip of the head to the end of the back shell. The 

 pincers of one of the tail claws are furnished with knobs, and 

 those of the other claw are serrated. With the former it keeps 

 firm hold of the stalks of sub-marine plants, and with the latter, 

 it cuts and minces its food very dexterously. The fecundity of 

 the Lobster is very great. Dr. Baster says that &quot;he counted 

 12,444 eggs under the tail of one female lobster, besides those 

 that remained in the body unprotruded.&quot; In a boiled lobster 

 they are bright red and called the coral. Lobsters are very 

 voracious, and are caught at night in pots or traps made of twigs 

 baited with garbage, (refuse flesh, entrails, &c.,) or in nets let 

 down into the sea, the place being marked by a buoy. Some 

 times they are taken by torch light, with a pair of tongs or for 

 ceps of wood. Their eyes are placed so that they can see in 

 every direction. When alarmed, they spring to a surprising 

 distance. Usually they weigh one or two pounds, but sometimes 

 four or even six. 



The COMMON LOBSTER of this country, Homarus, (Astacus,) 

 Americanus, (see Chart.) is, however, much larger, averaging in 

 weight four pounds, and sometimes reaching the weight of fifteen, 

 twenty, and even thirty pounds. The Common Shrimp of Europe, 

 Crangon, (Gr. krangon, a shrimp ) vulgaris, is closely allied to 

 the shrimp of our own country ; it is of a pale greenish color, 

 about an inch and a half or an inch and three-fourths in length. 

 The C. sept.emspinosus, (Lat. seven-spined.) is known by the 

 name of Bait shrimp, and extensively used. It is found from 

 Florida to the Arctic regions. 



(3) Anomoura, (Gr. anomalous tail.) This is a section inter 

 mediate to the two preceding, including crabs having the front 

 part of the body crustaceous; the lower part soft and rolled 

 upon itself. They are in the habit of resorting to the dead shell 

 of a univalve mollusk, which is exchanged for a larger one as 

 they increase in size, and seem to prefer the shells of the Tro- 

 choida, (see Chart.) Hence they are called HERMIT CRABS. 



SECOND ORDER. TETRADECAPODA, (Gr. fourteen-footed.) 



This includes several families of small Crustaceans, some of 

 them marine or fresh-water species; some of them terrestrial or 

 parasilic, which, from the number of their feet, may be referred 



