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 branchiz 
is built up. 
The male offers only specific variation from that of 
our British species. 
