Guide to Crustacea. 
Table-case 
No. 13. 
Table-case 
No. 14. 
68 
; of the genus Ebcdici. They are small Crabs, resembling the pebbles 
among which they are found. Specimens of Ebcdici tubcrosa are 
shown in their natural surroundings in Wall-case No. 11. 
In the family Dorippidae the afferent branchial openings are 
in front of the bases of the chelipeds. The abdomen is not com- 
pletely concealed under the cephalothorax. The last two pairs of 
legs are elevated on the dorsal surface of the body, and have the 
terminal segments more or less distinctly modified to form a pre- 
hensile claw. The Dorippidae appear to have given up the sand- 
burrowing habits characteristic of other Oxystomata, and they 
conceal themselves by holding a piece of sponge or some other 
object over the back by means of the hinder legs. Many of the 
species inhabit the deep sea. 
In the Baninidae the water seems to enter the branchial 
chamber from behind, between the edge of the carapace and the 
bases of the last pair of legs. As in Dorippidae, some of the 
abdominal somites are visible from above, and the last pairs of legs 
are elevated on the dorsal surface. The legs, however, are flattened 
and paddle-like, and appear to be used for swimming and digging, 
as in Mcitiitci. The “frog-crab,” Banina scabra, is, in general 
appearance, one of the most striking and aberrant of the Brachyura. 
In the Tribe Oxyrhyncha the carapace is usually triangular in 
shape, narrowed in front, and produced to form a rostrum. The 
mouth-frame is square. The genital ducts of the male open on 
the bases of the last pair of legs. As a rule, the legs are long and 
slender. 
The Crabs of this tribe are generally sluggish and inactive 
animals, and many of them, as already mentioned, have the habit 
of masking themselves with seaweed, sponges, etc. This habit is 
illustrated by some of the preparations in Wall-case No. 6, and 
evidences of it will be noticed on many of the specimens in this 
case. 
The members of the family Maiidae are known as “ Spider- 
crabs.” In these, the chelipeds are very mobile, and are usually 
not much stronger than the other legs. The orbits are more or 
less incomplete. Among the specimens exhibited may be men- 
tioned Macropodia longirostris, a common British species which 
has the long and slender legs that are typical in the group. 
Hucnia proteus is noteworthy for the leaf -like expansions of the 
carapace ; in life it is of an olive-green colour and is difficult to 
detect among the foliaceous sea- weeds which it frequents. To 
this family belongs the large Spider-crab of the South and West 
