192 ANCEID®. 

basal joints followed by two longer ones, the fourth being 
somewhat larger than the third, and followed by aslender 
setose six-jointed flagellum. The inferior surface is 
covered by two pairs of appendages (the gnathopoda), 
the outer of which appears to consist of only two distinct 
joints, although traces may be observed of their being 
composed of several joints closely soldered together 
(fig. g.¢). The first of these joints is rather wide, flat- 
tened, and considerably angulated beyond the middle, the _ 
basal half being more curved and the distal half nearly 
straight ; this is followed by an elongate-ovate joint, 
setose at its extremity; and in certain positions we 
perceived an indication of a very minute apical articu- 
lation amongst the terminal sete. Within this pair of 
appendages lies a pair of extremely delicate, flat mem- 
branes, which we have above regarded as the anterior of 
the incubatory scales, and within these are a second pair 
of appendages (first pair of gnathopoda), similar in form 
