Decapoda — BracJiynra. 



73 



rlonj^ated, extending over the front edge of the mouth-frame. The Table-case 

 latter character recalls the Oxystoniata, which the members of this ■^°- ^^• 

 family also resemble in their sand-burrowing habits. CorjidcH 

 (■(issivelaunus (Fig. 49) is a common British species. The claws 

 or chelipeds are much elongated in the male. The antennae 

 are much longer than is usual in the Brachyura, and each bears 

 a double row of bristles so arranged tliat when the antennae are 



Female. 



Male. 



Fir,. 40. 

 Curystcs cassivclaiiiius (slightly reduced). ; Table-case No. 15.] 



brought together they form a tube, through whicli respiration can 

 be carried on while the animal is I'juried in sand. 



In tlie trilie Catomktopa the carapace is typically more or less 

 quadrate, with the front strongly bent downwards ; tiie mouth- 

 frame is square ; the genital ducts of the male open on the sternum. 

 A large proportion of the Cral)s belonging to this tribe live on 

 land, in fresh water, or between tide-marks on tropical shores. 

 Only the chief families are illustrated in this Case. 



The family Gcocarcinidae (or Gccarcinulae) comprises the true 

 Laud-Ciabs, although some members of the other families also 



Table-case 

 No. 16. 



