68 



The spines on the chehpeds of the adult male are much reduced 

 compared with those on the female or the young male. 



The extreme tip of the chelipeds is characteristic of the species. 

 Both fingers end in a broad, curved tooth which terminates 

 the inner margin, and above this there is another smaller and 

 sharper tooth in line with the outer margin. 



The second, third, and fourth pereiopods resemble one another 

 closely, and are of much the same size ; the merus and propodite 

 are long, the other joints short. All three end simply. 



The fifth pereiopods are very feeble, and are usually carried 

 folded on themselves, and half inside the branchial chamber. 

 The merus and carpus are long and slender, the flexure taking 

 place at their point of articulation. The appendage ends in a 

 small chela, thickly covered with setae. 



The pleopods are quite different in the two sexes. 



In the male the first pair of pleopods consist of a slender 

 peduncle, which is followed by a single lamellar joint of peculiar 

 structure. It consists of a thin plate, the inner edge of which 

 is curved, and is fringed with short bristles ; the outer edge is 

 not curved except near the distal end, where it is folded inwards, 

 so as to form a flap, which bears some longer bristles. The second 

 pleopods are longer than the first, and consist of a fairly stout 

 peduncle, at the end of which there is a small blunt process 

 of one joint which represents the exopodite. The endopodite 

 slopes inwards and broadens out half-way to the tip, after which 

 it narrows again ; the distal half has a covering of short, stiff 

 bristles. This portion probably represents the appendix masculina 

 united to the endopodite. The third, fourth, and fifth pairs of 

 pleopods have thin lamellar peduncles, which are straight on 

 the outer side and curved on the inner ; the latter bears a row 

 of long plumose hairs from seven to fourteen in number. At 

 the extremity of the exterior margin there is a short, blunt 

 process representing the endopodite. Of this process Bonnier 

 says : " a son extremite distale . . . se trouve un rameau interne, 

 d'un seul article et tres reduit." In the large number of speci- 

 mens collected by the Helga quite a number of males have this 

 process composed of two joints. In the majority of cases those 

 in which two jo nts are present are larger than those with one. 

 Altogether fifteen males have only one joint, and eight have 

 two. In some of the latter the second joint is much shorter 

 than the first, while in others the two joints are equal. 

 Probably the possession of one or of two joints depends upon 

 age. 



In the female the pleopods of the first segment are altogether 

 absent. Those on the following segments are slender and three- 

 jointed. 



The borders of the uropods are furnished with fringes of long, 

 pinnate setae, and also bear rows of large and small spines. The 

 spines are best developed on the posterior edge of the endopodite. 

 The surface also bears small groups of spines and bristles, 

 all pointing backwards. 



