103 
(R) are the rostral plates, which in this stage lie widely apart, but will subsequently 
meet in front, to form the pseudo-rostral projection. In the interior of the 
body, the coarsely granular, opaque yolk-mass is still visible; but it has consider¬ 
ably diminished in volume, having been chiefly consumed to form the liver (1), 
which now appears as 2 rather large sac-like organs extending backwards below 
the yolk-mass. 
The stage represented in fig. 8 at first sight looks very different from 
the preceding one; but in reality it immediately succeeds it. The chief difference 
consists in the disappearance of the dorsal curvature of the body, this having been 
changed to a pronounced ventral one, and in the consequent projection of the 
limbs forwards instead of backwards. The embryo in this stage has very little 
resemblance to an Isopod-emhryo, whereas it agrees much more with that of a 
decapodous Crustacean. The anterior division of the body is still broadly 
rounded, or almost truncated in front; but its posterior (exposed) part has now 
become distinctly segmented, the number of segments agreeing with that in the 
adult animal. The last segment, however, is very small and still without any 
trace of limbs. The posterior division, or tail, is about the length of the 
anterior, and is bent in against the ventral face of the latter. It exhibits the 
normal number of segments, which are very distinctly defined and of nearly 
equal size, the last carrying a well-defined telson between the uropoda. At the 
anterior extremity the eyes (0) are distinctly seen. They are still well defined 
from each other, though in somewhat closer proximity than in the preceding stage, 
each forming a rounded capsule, in which 3 visual elements have already devel¬ 
oped (see fig. 9). The superior antennae (a 1 ) are rather large, and are extended 
obliquely forwards, sometimes with their outer part curved more or less upwards. 
The 3 joints of the peduncle are indicated by distinct instrictions, and the flagella 
also exhibit traces of segmentation. The inferior antennae (a 2 ) have stopped 
in their development, being scarcely larger than in the preceding stages. The 
mandibles (M), on the other hand, are much more fully developed and have 
assumed their definite form and position, their upper pointed extremity being 
articulated to the carapace at the place where the rostral plates originate. The 
post-oral appendages are closely crowded together, and in form and mutual 
size approach those in the adult animal, though not yet functionally developed. 
The exopodites have wholly disappeared in the last 2 pairs, as also in the pair 
representing the 2nd pair of maxillipeds. In the preceding pair, representing 
the 1st pair of maxillipeds, it has considerably increased in length and extends 
straight forwards, its outer part (br. exp.) having the form of a narrow lingui- 
form plate. Besides this exopodal part, the epipodal part may also be traced 
