Cli USTA CEA S YS TEMA TIC HE VIEW 



299 



gurus, Birrjus (in holes in the ground). Hippidce, marine, live in mud ; posterior 

 body hard skinned, the half of it bent forwards. The Galateidce (Galatea] approach 

 the Macnira, and the Porccllanidcc (Porccllana) the Brachyura. 



FIG. 203. Astacus fluviatilis, from the ventral side. A, male ; 7J, female. In the male the 

 8th to 13th and 15th to 18th extremities of the left 'side of the body are removed ; in the female the 

 ~2i\ and 4th to 13th of the right side. 3-13, Extremities of the cephalo-thorax ; a.i-a<>, anterior and 

 posterior antennae ; gd, aperture of the antennal glands ; wo, female ; mo, male genital aperture ; 

 l'i-2'Gi pleopoda ; en, endopodite ; ex, exopodite of the last pair of pleopoda ; an, anus; t, telson 

 (after Huxley). 



Sub-Order 3. Brachyura (Crabs). 



Body flattened. Posterior body without anal fin, reduced, bent round on the 

 ventral side of the cephalo-thorax. In the male only the two anterior pairs 

 of pleopoda are usually retained. Notopoda, in the sea : Dromia, Dorippc, Lithodes. 

 Oxystomata, round crabs : Calappa, Ilia, in the sea. Oxyrhyncha, tri&ngul&r crabs : 

 Maja, Pisa, Stcnorhynckus, Inachus, Lambrus, in the sea. Cydomctopa : Tdphusa 



