n8 ECONOMIC ZOOLOGY AND ENTOMOLOGY 



wegian lobster, Nephrops norwegicus. Around the islands off 

 the coast of California is a large crustacean about the size of 

 the eastern lobster, but the front legs are not enlarged 

 into the great heavy pincers. It is often referred to as the 

 spiny lobster, or "salt water crawfish." It belongs to the 

 genus Palinurus, which is represented in different parts of the 

 world by several species that are highly valued as food. 



Shrimps and Prawns. The prawns, which are marine and 

 much like the lobsters but very much smaller, and the shrimps, 

 which occur in both fresh and salt water, are often much sought 

 after for food. They often occur in great "schools," and are 

 caught in nets or dredges, sometimes in great numbers. They 

 are put fresh directly on the market, or are canned and 

 shipped to all parts of the world. The principal shrimp fish- 

 eries are along the shores of the Gulf of Mexico where the 

 common shrimp, Crangon milgaris, is exceedingly abundant. 

 Most of the canned shrimp come from this region. The same 

 species occurs on the Pacific coast where, however, the Cali- 

 fornia shrimp, C. franciscorum, is more important. Besides 

 supplying the local markets with the fresh shrimp the California 

 Chinese formerly dried great quantities of them. The dried 

 meat was separated from the shell and exported, the value 

 of the export reaching $100,000, in some seasons. 



Some of the largest and finest prawns and shrimps are 

 found in Puget Sound, but the demand for them is so great 

 that they seldom get beyond the local market. Like the 

 lobster fisheries, the shrimp fisheries have suffered from lack 

 of intelligent regulation. 



It should be noted that these crustaceans, which occur in 

 untold numbers in so many waters, form a large part of the 

 food supply of many of our important food fishes, and the 

 destruction or material reduction of this source of food has 

 an effect more far-reaching than at first appears. 



The hermit crabs, which are more nearly related to the 

 shrimps and prawns than to the true crabs, found along all 

 seashores, well illustrate the structural changes that may be 

 brought about by a special or peculiar mode of life. Very early 

 the young animals seek out an empty shell, such as a snail or 



