439 
The internal organs have been omitted: the condition of the ovisacs 
mentioned below proves that the emission has been uecessary. 
The Cephalothorax is exceedingly swolleii, subglobular, in the 
dissected specimen of equal length, breadth and depth, in the otlier 
specimen (fig. 2) even considerably broader than long or thick. The 
swollen portion consists essentially ouly of the head and the first 
thoracic segment, while the other thoracic segments constitute together 
a low oblique cone which is very small as compared with the head. 
The skin on the dorsal and lateral surface of the head is thin 
submembranous. On the ventral side the head is separated from 
the first thoracic segment by a narrow transverse stripe (fig. 4, /) 
of membranous skin, but on the sides and on the back a folding 
of the skin of this strongly vaulted part prevented me from deciding 
the question, but most probably the first segment is here coalesced 
with the head. The rostrum (fig. 4, d) is short, depressed and with 
the end broadly rounded; it occupies the whole space between the 
basal joints of the antennulæ. 
The Antennulæ (fig. 4, fig. 5) are a little longer than the 
maxillipeds without their terminal hook (compare fig. 4 with fig. 10: 
both drawn with the same degree of enlargement) and as long as 
the free thoracic segments and the abdomen together. In fig. 4 the 
left antennula (and the proximal portion of the right) is shown in 
thé position in which I found it: is turns the front side essentially 
downwards, and it is therefore the anterior half of the antennula 
which is shown in that figure. Fig. 5 shows the right antennula 
from above; especially this drawing elucidates the essential features, 
The antennulæ consist of twelve very distinet joints. The second 
and third joints together are only as long as the first or the fourth; 
the fourth joint shows on the upper side a vestige of a division 
into two joints. The fifth joint, which is as long as the fourth, is 
very peculiar, its anterior half being distally produced as a rather 
short and very broad, rounded prolongation covering anteriorly as a 
cap the major part of the following short joint. The seventh joint 
is nearly as long as the three proximal joints together; seen from 
