8 T. V. HODGSON. 
In the female the first appendage of the mesosome is comparatively small; the 
ischium is produced as a rounded lobe, much narrower than that of the male, below 
the point of its articulation; the merus is not very different to that of the male ; 
the carpus is cylindrical; both these joints bear a pair of long setz. The propodus 
forms a well-developed chela; the two dactyli are stout and subequal in size, with 
discoloured teeth at their extremities. The immovable finger has a long seta on 
either side of its base and another pair on the inner margin close to a series of four 
small teeth which end against the terminal tooth. 
In the female the first leg is slender, the first joint is as long as the succeeding 
four, the second is very short, and the others progressively lengthen and have a few 
sete distally ; the sete are strongest at the extremity of the limb; the terminal 
claw is very slender and more than half the length of the joint which bears it. 
The two following legs are similar, but the terminal claw shortens. The last three 
pair are a little shorter and stouter, the setee are more spinous, and the terminal 
claw is comparatively short and more definitely a claw. Those of-the male are 
similar, but longer and more slender. The oostegites number four pairs, and are 
attached from the second to the fifth appendages of the mesosome. Lach oostegite 
consists of a rather broad strap-like axis, from each side of which extends a very 
delicate membrane, the whole forming a concave structure nearly round in shape. 
The pleopods are five pairs of the appendages adapted for respiration, and are 
similar in both sexes. Each consists of a protopodite of two joints, the first of which 
is very small, a large endopodite, ovoid in shape, the inner margin of which is fringed 
with stiff setee, and these increase in size to the distal extremity. The exopodite 
is much smaller, slightly curved, and its inner margin is similarly setose, but the 
setze are much reduced in number; the posterior pleopoda differ slightly in shape. 
The exopodite is attached half way along the second joint of the protopodite. 
A very large number of specimens were collected during the whole of our stay 
in Winter Quarters. They were constantly being picked out of the sponge débris and 
obtained inside the 25-fathom line. It would appear from the great number of 
individuals of all ages and sizes that the acquisition by the male of the enormously 
developed chelipeds takes place suddenly. There were no specimens which indicate 
a gradual development of these organs, nor were there any specimens of small size 
showing this distinctly masculine character. A large proportion of the apparently 
adult females show no trace of oostegites, and it is quite possible that some at least 
were not completely developed males. The suddenness of the change is also 
emphasized by the fact that the mouth organs of the fully developed male are 
defective. 
LEPTANTHURA. 
Leptanthura G. O. Sars (13), pp. 47-48. 
This genus was instituted by Prof. G. O. Sars in 1899, being separated from 
Paranthura by a number of small characters. The mouth organs seem to be the 
