RIVER CRABS 77 
which Krauss found at a waterfall in Natal, is yellowish 
and orange-coloured, in accordance with the cushions of 
moss among which it has its residence. Thelphusa 
dehaanii, White, occurs in the paddy fields of Japan, and 
has been taken at an elevation of 2,500 feet above the sea- 
level. It has been already mentioned that the river crab 
of Europe is good eating. Milne-Edwards supposes that 
it was to this crustacean that Aristotle referred under the 
name Carcinus Heracleoticus. 
Paratelphusa, Milne-Edwards, 1855, was at first sup- 
posed to be a marine genus, but has since been proved to 
be an Indo-Malayan genus of fresh-water crabs, several 
species of which have been described by Mr. Wood-Mason. 
They differ from the rest of the Thelphusidae in having the 
distal end of the fourth joint of the chelipeds armed with 
a sharp spine, and are also said to have a greater general 
resemblance to some of the Cancride. 
Dr. de Man, in his elaborate Report on the Podoph- 
thalmous Crustacea of the Mergui Archipelago (‘ Journ. 
Linn. Soc.’ 1887, 1888), includes the genus T'helphusa in 
the next tribe, and the same arrangement is followed by 
Dr. Camil Heller in his ‘ Crustacea of the Novara,’ 1865, 
the Thelphusinea being in fact intermediate in structure 
between the Cancride and the Gecarcinide. 
