416 
CHIYOMATSU ISHIKAWA. 
the start. From the embryo of Panopeus (yg-) it differs in 
the fact that the second pair of maxillae of that Crab is bilobed 
from the beginning, and is not single as in Atvephira. 
At the base of the second pair of antennae is now seen the 
first trace of the antennal gland (fig. 68, gg., and fig. 90). The 
ectoderm cells group themselves at this spot into a circular 
mass, the cells of which are well distinguishable from other 
cells by their regular roundish shape. 
The superficial ectodermic cells of the cephalic lobes (fig. 68, 
oc.) become marked off from the inner layers. The labrum 
(fig. 68, lb.) pushes downwards, so as to lie between the second 
pair of antennae (fig. 68, At. 2). Beneath the labrum is seen 
the oesophagus (fig. 68, as.) as a square opening. New thoracic 
segments become visible behind the first pair of maxillipedes. 
The abdomen gets larger, and its end becomes bilobed. In the 
notch between the two lobes is the anus (fig. 68, an.), bounded 
by about thirteen or fourteen cells. Continued from the anus 
is seen the latter part of the intestinal canal, lined with 
columnar epithelium. No nauplius eye has as yet appeared. 
In fig. 69 all the pairs of the maxillipedes (mxp. 1, 2, and 3) 
have appeared. Both antennae {At. 1 and 2) have changed 
considerably. The cephalic lobes become more definite in out- 
line. The cells of the superficial ectoderm, which later become 
the crystalline cones, elongate. The abdomen gets still longer; 
five succeeding segments behind the third pair of maxillipedes 
have appeared, and the future telson is marked off from the 
abdomen at the sides. The outline of the carapace is now 
seen extending to over the third pair of maxillipedes. The 
depression of the antennal gland becomes deeper. 
Fine nervous striations now become visible within the 
supra-oesophageal cellular mass (fig. 69, sgn.), whence the 
branches are given out first to each of the cephalic lobes. 
Each of these branches sends out a branchlet near its base to 
the median ocellus (oc/.), the nauplius eye, which is now 
formed. Behind they i’un downwards and surround the 
oesophagus, giving off branches to both antennae. 
Traces of the nervous striae are also seen faiutlv on each 
