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 may be 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 Paleemon, Ranina on 
fishes and starfish. Calappa gallus (Herbst) is common to 
the Atlantic andthe 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 Calappa and 
