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. Hegner. The MacmiUan Co., N. Y. City. 

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



City. 



