254 BOPYRID^. 



near the middle of each organ. On each side, near the 

 posterior extremity, exist two digital processes, the 

 secondary appendages of the maxilla. The maxilliped 

 consists of three primary joints, the first two being large 

 and squamous, the third small and rudimentary. Posterior 

 to the point where this joint articulates with the pre- 

 ceding, lies the secondary appendage which, like those 

 of the preceding pair, is digital in form, and points 

 backwards. 



The appendages of the pleon consist of three kinds, 

 namely, a primary branch minutely articulated through- 

 out its length ; the basal articulus, which probably 

 represents the coxa or first joint in the normal organ, 

 supports two appendages, one large and saccular, being 

 constricted at the base and pointed at the apex, the other 

 long, narrow, symmetrical, and pointed. These two ap- 

 pendages are constant on every pair of pleopoda, but 

 bear an inverse proportion to each other. In the anterior 

 pair the saccular branch is the more important, but 

 this gradually diminishes on each to the last pair, 

 where it is almost, if not quite, obsolete, whereas in the 

 first pair the digitiform process is the smaller of the 

 two ; this gradually increases on each succeeding pair 

 of pleopoda, until in the last pair it forms the long- 

 pair of caudal processes seen so conspicuously at the 

 extremity, and to which in this present species the male 

 was attached by means of the subprehensile claw of the 

 posterior pair of pereiopoda. To all the segments, except 

 the last, are attached one or more of the numerous 

 arborescent branches of which the mass of branchiae 

 is built up. 



The male offers only specific variation from that of 

 our British species. 



