138 



NATURAL HISTORY. 



Fig. 126.— Alpheus heterochelis, showing the enor- 

 mous development of the pincer; slightly en- 

 larged. 



into a corresponding cavity in the 'thumb.' When alarmed, these animals 

 rapidly open and shut their pincers, and this tooth, acting like the pulling 



of a cork from a bottle, makes a 

 noise like that of snapping the 

 finger-nails, and so loud that it is 

 out of all proportion to the size of 

 the animal. Other species of Al- 

 pheus are almost parasitic, and live, 

 as do some allied genera, inside the 

 shells of bivalve molluscs. 



The other genus to be mentioned 

 is like Alplieus in having no common 

 name. In science it figures as Spongicola, and this name is very appropri- 

 ate, as the animal is found within the cavity of the Venus's flower-basket 

 sponge, as was mentioned on a preceding page. It obtains entrance when 

 very young and still small enough to pass through the meshes of the 

 sponge, Imt it soon grows so that it remains a prisoner for life. Another 

 crustacean, which we will meet later in these pages, shares this habitat 

 with the shrimp, and is even more abundant than it. 



The lobsters and cray-fishes are near relatives of the shrimps and 

 prawns, but they exhibit such modifications of their structure as to place 

 them in a higher plane. When alive, the lobster is prettily colored, his 

 shell being marked with green and purple, dotted and spotted here and 

 there with, bright red; wdiile the size and strength of his large pincers 

 render him formidable and rather dangerous to handle. There are three 

 species of true lobsters (Homarus), but the differences between them are 

 n<>t appreciable by the layman. Our plate represents on the left the Euro- 

 pean species ; but for all practical purposes, it will answer for the American 

 as well. They are all found near the shore in water of moderate depth, 

 ami. like almosi all crustaceans, are scavengers, feeding on dead and decay- 

 in- animal matter. It is astonishing how quickly a dead animal will be 

 cleaned of its flesh if put in the sea. It soon swarms with crustaceans of 

 all sizes, from the large lobster and crab to the small and even microscopic 

 forms, the smaller individuals making up in numbers what they lack in 

 size. 



Our American lobster is one of the largest of crustaceans. To-day 

 extensive fishing does not allow it to reach its full size, and now it is rarely 

 that big ones are taken. In former times they were not uncommon. The 

 largesl specimen which the writer has seen weighed twenty-five pounds, 

 bui he has also seen the claw of one taken years ago, at Gloucester, Mass., 

 winch was said to weigh thirty-nine pounds, and the size of this member 



