ANCKEUS. Eig 
ovi-pouch: the young of one animal appearing to be 
all males, those of another being all females, so that 
the variation may have been the result of an older or 
younger stage of development. 
But, however great the similarity may be between the 
two sexes at the time of their first leaving the ovi-pouch 
of the parent, they very soon exhibit a distinguishable 
variation, as seen in the woodcut on the preceding page, 
in which fig. 1 (of which la is an enlarged figure, seen 
laterally) represents the male larva. That of the female 
(figs. 2 and 2a, seen laterally) has the three posterior 
segments of the pereion losing their crustaceous and seg- 
mental character, and putting on that of a membranous 
condition, and becoming fused together into one long 
segment. 
That of the male, as shown in fig. 1, of which la 
is an enlarged representation (seen laterally), has the 
segments well defined and crustaceous, but the central, 
that is the third (though homologically the fifth), seg- 
ment of the pereion, considerably increased in length, 
with the coxe partially fused with the segment. Viewed 
laterally, this segment is dorsally elevated above those 

DEVELOPMENT OF ANCEUS. 
Fig. a. Young of Anceus Edwardii (p. 201). Fig. B. Eggs, Fig. c. Young 
of Anceus Maxillaris (pp. 176 and 192). 
VOL. II. N 
