56 
GAMMA RIM. 
The inferior margin of this appendage is, like the one 
last described, fringed with a row of equidistant solitary 
cilia. The fifth, sixth, and seventh pairs of legs are 
uniform, except that the second joint of the fifth pair 
is not developed like a scale, which is the case with the 
second joint of the two other pairs. Their first joints 
are small, almost rudimentary, and exhibiting but slight 
traces of their scale-like character. In all other respects 
the last three pairs of legs resemble in appearance those 
of the two preceding pairs, with the exception of being 
affixed in a reversed position, according to the common 
type of the order. 
The three pairs of swimming appendages are long and 
slender. The three pairs of caudal appendages are 
strong, stiff, and pointed ; the penultimate is shorter 
than the other two. The last pair has its branch with 
the apical joint nearly as long as the preceding. The 
terminal scale is ovate, fringed with three or four short 
hairs. 
The colour of this species is white, or fiesh-colour, 
marked with a large blotch of bright crimson on the 
back and side, and with a few darker spots of the same 
colour, as represented by the shading in the accompany- 
ing figure. A single specimen that we obtained from 
the neighbourhood of the Eddystone Lighthouse was 
marked all over with red spots. It only appeared to 
differ from the present species in having the palm of 
the hand of the second pair of arms slightly crenulated. 
It appears not to be uncommon on our shores : it is a 
sublittoral species, and exists probably all round Europe, 
being found beneath stones in pools, near low water at 
spring-tides. 
It has the capability of rolling itself very perfectly 
within the defensive armour provided by its largely- 
developed coxae. 
