134 



FIRST BOOK OF ZOOLOGY. 



look like plumes. This space may be called the gill-chamber, 

 and the water flows into it by passing under the edge of the 

 carapace back of the big claws, and passes out of an opening 

 near the mouth-parts. The currents of water flowing in to 

 the gill-chamber are induced by a stiff appendage attached to 

 the base of the second pair of maxillse called the fldbellum 

 (see Fig. 125), and which swings back and forth and scoops 

 the water into this chamber. These gills are shown as they 

 appear in the crawfish. In tearing off the claws of the 

 lobster, the gills are often drawn out too, and remain attached 

 to the base of the legs. In the lobster the carapace can be 

 easily bent up, so as to show the gills. 



In the following figure a crawfish is shown with a portion 



cepJialo-thorasa abdomen 



small antenna, 



large antenna ^??? 



mandible 

 maxilla; -j j 



maxillipedts .' 



C f E A 



FIG. 125. CRAWFISH SEEN FROM THE SIDE, WITH THAT PORTION OF THE CARAPACE REMOVED 

 "WHICH COVERS THE BRANCHIAE OB GlLLS. THE APPENDAGES OF THE LEFT SIDE ONLY 

 SHOWN. s, Region of Stomach ; A, Abdominal Appendages ; B, Bases of the Four Small 

 Legs; C, Base of Large Claw ; /, Flabellum attached to the Second Maxillipede ; 0, Eye. 



