HOMARUS AMERICANUS Milne-Edwards 



Material. Specimens of the American lobster may be 

 obtained from the Woods Hole Marine Laboratory or from any 

 of the other marine laboratories. Every student should re- 

 ceive a specimen preserved in weak alcohol and another with 

 the circulatory system injected. 



Descriptive Part 



Homarus americanus or the common American lobster is a 

 typical representative of the Suborder Decapoda, Order Mala- 

 costraca, Class Crustacea. It is an inhabitant of the Atlantic 

 Coast, where it is found in great numbers below the low- tide mark. 

 Unfortunately, owing to its gastronomic qualities, the older 

 and larger specimens become more and more rare. The largest 

 lobster on record is at present in the American Museum of 

 Natural History in New York. It was caught in 1897 at the 

 Atlantic Highlands, N. J., is twenty- three and three-fourths 

 inches in length and weighed when alive thirty-four pounds. 

 Its crushing claw is fifteen inches long. The food of the lobster 

 consists chiefly of fish, live or dead, and to a smaller part of 

 invertebrates. Although much more highly developed than 

 the little Daphnia, the lobster shows much better the segmenta- 

 tion of its body. 



External features and segmentation. To avoid repeti- 

 tion, the minute description of the external features of the lobster 

 will be given in the "Instructions" at the end of this chapter. 

 We are here concerned with the general principles of the struc- 

 ture of its body. 



The body of the lobster is composed of twenty-one somites 



