

144 PRACTICAL ZOOLOGY 



dominal segments are generally narrow and more mobile than 

 those of the head and thorax ; they bear appendages which are 

 often reduced in size. 



A convenient method of classifying the Crustacea is to place 

 them in two subclasses. 



Subclass I. Entomostraca. — Fairy Shrimps, Water Fleas, 

 Cyclops, and Barnacles. 



Subclass II. Malacostraca. — Pill Bugs, Sow Bugs, Beech 

 Fleas, Shrimps, Crayfish, Lobsters, and Crabs. 



REFERENCES 



The Life of Crustacea, by W. T. Caiman. — Methuen and Co., London, 



England. 

 Higher Crustacea of New York City, by F. C. Paulmier. — N. Y. State 



Education Department, Albany. 

 College Zoology, by R. W. Flegner. — The Macmillan Co., N. Y. City. 

 The Sea Beach at Ebb Tide, by A. F. Arnold. — The Century Co., N. Y. 



City. 



