46 ORDERS. 







2. STOMAPODIA, body-footed. Head distinct 

 from the trunk, and divided into two parts ; and the 

 fore part bears the antennae and the moveable eyes ; 

 mandibles bearing palpi. 



The gills are plume-like. 



Example. Crawfish. 



8. AMPHiFODiA ?t /e^ all the length of the body. 

 Head distinct from the body, being one piece only ; 

 eyes immovable ; mandibles bearing palpi. 



The gills or respiratory organs are vesicles si- 

 tuated at the interior base of the feet. 



Example. Gamrnarus. 



4. ISOPODIA, equal footed. Head generally dis- 

 tinct from the trunk ; mouth composed of several 



jaws ; mandibles without palpi, but the two lower 

 jaws resemble a lip bearing two palpi, 



Gills or respiratory organs generally situated 

 on the under side of the trunk. 



Examples. Oniscus, sowhug. 



5. BiiANcmi'ODKS, gills or respirable organs on 

 the fin-like feet. Mouth is sometimes in the form 

 of a beak, other times composed of many jaws ; 

 no palpi. 



Examples. Limulus, cecrops, cyclops. 



VII. CLASS ARACHNIDA 



IS DIVIDED INTO TWO ORDERS. 



d. PULMONAIUA, having pulmonary or respira- 

 tory sacks 



Examples, Aranea or proper spider^ mygale^ 

 tarantula, scorpion. 



2. TRACHENIA, respiratory organs are trachea 

 or radiated and branched tubes. 



