VI 



FAMILIES OF CVCLOMETOPA 



swimming. 



The carapace is sub-circular, and the rostrum short and toothed. 

 J/VAr7/r///x, European seas. 



Fam. 3. Cancridae. The carapace is broadly oval or hexa- 

 f-onal, and the flagella of the second antennae are short and not 



O ' 



hairy as in the foregoing. The first antennae fold lengthwise. 

 Carcinus maenas on English and North European coasts. This 

 crab has become naturalised in some unexplained manner in 

 1'ort Phillip, Melbourne. Cancer in North Atlantic, North 

 Pacific, and along the west coast of America into the Antarctic 

 regions. C. 2Mgurus is the British Edible Crab. 



Fam. 4. Portunidae. The legs are flattened and adapted for 



The first 

 fold back 



antennae 



transversely. Portu- 

 nus, Atlantic and 

 A I < 1 i terr; mean. Nep- 

 tunus, Indo - Pacific. 

 Callinectes, C. sapi<ln*, 

 the edible blue Crab 

 of the Atlantic coasts 

 of America. L />/><> 

 (Fig. 131). 



Fam. 5. Xanth- 

 idae. The first an- 

 tennae 



versely, but the legs 

 are not adapted fur swimming; the body is usually transversely uv;il. 

 This family is especially characteristic of the tropical lit tural, where 

 it is very widely represented. Xantho,Actaea,Chlorodius, I'llmnim*. 

 Ki-i i>h in, with ti. j>i /afro //.s, euiiimon in the, Mediterranean. 



Fam. 6. Thelphusidae (Potamonidae).- Kresh-\\ater crabs, 

 with the branchial region very much swollen. Thelphusa or 

 I'ntu I/IDII) lias nearly a hundred s^ieeics distributed tVum N'urih 

 Australia, through Asia, Japan, the Mediterranean region, ami 



fold trans- FlG- ^l. Dorsal view of LiqM. li<t*/"ta, x 1. (From MM 

 original drawing prepared for I'rol'essur Wuldon.j 



throughout Africa. 



Potamocarcinus in tropical America. 



Tribe 4. Oxyrhyncha. 



This section includes the. Spider-crab-' and related gem 

 in which the carapace is triangular, \\iih I he apex in linl 



