70 A Guide to the Zoological Collections in the 



orbits, and there are cavities into which the short anten- 

 nules can be folded. The maxillipeds have lost their 

 foot-like appearance, and the last (third) pair have the 

 basal joints expanded to form complete doors in front of 

 the mouth. 



The disarticulated specimen of the common Indian 

 edible crab [Scylla serrata) in Case 49 should be carefully 

 compared with the neighbouring disarticulated specimens 

 of Penasus and Nephrops. 



The majority of the Crabs are marine, but there are 

 numerous fresh-water species, and a good many species 

 live entirely on land quite remote from either sea or river. 

 The great majority of the marine species are found with- 

 in the hundred-fathom line, and although about sixty spe- 

 cies have been dredged at greater depths, only two or three 

 have been taken in water over a thousand fathoms deep. 



The Brachyiira are subdivided into five tribes — Cy- 

 clometopa, Catometopa^ Oxyrhyncha, Oxystomata, and 

 Anoinala, the last presenting a considerable resemblance 

 to some of the Anomura, e.g., to the Hippidse. 



ist Tribe, Cyclometopa. Cases 65-67. — This tribe in- 

 eludes the common edible crabs, the swimming crabs, and 

 the common Indian fresh-water crabs. The carapace is 

 generally very much broader than long, and often forms a 

 wide nearly semicircular arch in front : the chelae are 

 usually very large and powerful. Many of the members 

 of this tribe reach a large size, and most of them are very 

 bold and active. They are arranged in numerous families, 

 five of which are well represented in the Gallery. 



ist Family, CancridaB. — Chiefly reef-loving crabs. — 

 Specimens of the following Indian genera are 

 exhibited: Carpilius, Atergatis, Lophacta;a, 

 Lophozozymus, Actxa, Xantho^ ChlorodiuSy 

 Euxanthus, Epixanthus, Panopeiis, Chlorodop- 

 sisy Zozy?nus, EtisuSy Leptodius, Pseudoziiis, 

 Heteros/us, Pilumnus, Actumnus Menippe, 

 Eudora. 



