124 A HISTORY OF RECENT CRUSTACEA 



The third maxillipeds have the fifth and following joints 

 not wholly concealed by the fourth joint. The verges of the 

 male are exserted from the bases of the fifth pair of legs. 



There are about ten genera included in this family. 



Calappa, Fabricius, 1798, contains some fifteen species, 

 which are not a little remarkable in appearance. This is 

 partly due to the form of the carapace, much narrowed in 

 front where the short-stalked eyes twinkle cunningly, but 

 widened behind with shield-like expansions over the bases 

 of the legs. More singular, however, is the development 

 of the chelipeds, which have a very flat crested hand of 

 great size, yet the whole limb withal so arranged that the 

 pair can be concealed beneath the body to which in that 

 position they might be said to supply an operculum or in- 

 complete ventral carapace. Of Calappa' granulata (Linn.) 

 Stalio says that, when it is compelled by fear of some 

 enemy or by the force of the waves to leave its crevice in 

 the rock, it draws together its walking-legs under the ex- 

 panded parts of the carapace, makes its chelipeds meet, 

 and, being thus reduced to the shape of a ball, launches 

 itself into the deep. Unfortunately for it, the scouring of 

 the waves often throws it up on to the shore, where con- 

 tinuous rolling upon the pebbles puts an end to its exist- 

 ence. This is a waste of what would otherwise form an 

 agreeable morsel. It maybe eaten with a good conscience, 

 since it is itself very voracious, and when in pursuit of 

 prey not to be intimidated. Judging from the contents 

 of the stomachs of various Crustacea, de Haan was able to 

 decide that Calappa, Matuta, and Dorippe feed on other 

 Brachyura, Leucosia on species of Palcemon, Ranina on 

 fishes and starfish. Calappa gallus (Herbst) is common to 

 the Atlantic and the Pacific. The crested claws here carry 

 to an almost comical extreme the resemblance to the head 

 of a cock, which they exhibit more or less throughout 

 this genus. Calappa depressa, Miers (see Plate II.), from 

 the South Australian coast, is one of the smaller species 

 and a recent contribution to science. 



Paracyclois, Miers, 1886, is a genus in which the cheli- 

 peds and walking-legs agree with those in Galappa and 



