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DIRECTIONS 



For Collecting and Preserving Insects 

 and Crustacea. 



CLASS 1. CRUSTACEA. 

 Character. The Crustacea are divided into 

 two large groups or sub-classes: the animals of 

 the first sub-class, ENTOMOSTRACA, are distin- 

 guished by having their legs branchial, or fur- 

 nished with appendages ; mandibles wanting, 

 or generally simple; eyes sessile or peduncu- 

 lated. The animals of this sub-class are all 

 aquatic; it contains the Monoculus Polyphemus 

 of Linne", or King Crab, one of the largest of 

 the annulose animals ; it is found in the Indian 

 Seas, and several smaller species have lately 

 been discovered in America by Mr. Say. This 

 division also contains many extremely minute 

 animals at present but imperfectly known, the 

 few that are described being, for the most part, 

 European* Some of the Entomostraca are evi- 

 dently parasitic, being found attached to the 

 bodies of sharks and fishes ; others will be seen 

 on floating fuci and confervse, or when these 

 are left by the retiring tide, or thrown on shore 

 B 



