110 A HISTORY OF RECENT CRUSTACEA 
appearance of the females, especially in the widening of 
the pleon, which is the first characteristic of sex that would 
generally be looked for. It follows, therefore, that among 
the specimens which in old times have been regarded as 
spurious females many spurious males were beyond doubt 
included. It is also worth remembering that when the 
shape of the pleon leaves the sex of a crab ambiguous, that 
may be taken as an indication that some curious species 
of parasitic crustacean is likely to be found in some part 
of the organism. 
A large extension has been given to the family of the 
Inachidee by recent voyages of deep-sea exploration, and 
in some instances species which, when first discovered 
only a few years ago, were naturally supposed to be rare, 
have since proved to be cosmopolitan. Thus the little 
Lispognathus Thomsoni (Norman), a delicate species with 
long slender limbs, taken at a depth of two or three 
hundred fathoms in the Fiaré Channel, and first described 
in 1873, has since then been taken at much greater depths 
and at places so wide apart as the Straits of Gibraltar, the 
neighbourhood of the Cape of Good Hope, and of Sydney 
in Australia. 
Ergasticus, A. Milne-Edwards, 1881, has two species 
—Ergasticus Clouei, A. Milne-Edwards, and Ergasticus 
Naresii, Miers. The latter was taken near the Admiralty 
Isles in the Pacific, and recalls the name of the honoured 
captain of the Challenger; the former was found in the 
Mediterranean and the Atlantic, and the name of the 
genus founded for it signifies ‘a worker’ in remembrance 
of the French ship, the Travaillewr, by which the type- 
specimen was dredged. Platymaia Wyville-thomsoni (see 
Plate IV.), Cyrtomaia Murrayi, Cyrtomaia Suhmi, Echi- 
noplax Moseleyi, represent new genera and species in this 
family instituted by Miers in 1886, in which the specific 
names have been chosen expressly to associate some of the 
finest of the Brachyura dredged by the Challenger with the 
names of its staff of naturalists. Platymaia and Cyrtomaia 
are also pointed out as of especial interest from their ‘ being 
Malayasian representatives of a section of the sub-family 
