DR. M‘'INTOSH, ON THE CARCINUS MQ@NAS. 203 
sides of the body. This bifid portion (f, f) was filled with 
opaque cells and granules. Another (ventral) sucker (d) is 
situated a short distance below these ducts, in company with 
a smaller globule (e) placed above (in front of) it, and two 
larger circular masses (¢ and d) on each side. The former 
masses (c, c) were large granular structures, more opaque 
than the others. The large compound cells lay in two groups 
(k, k) just within the margin of the body, and when undue 
pressure was applied, they escaped through a central pore at a. 
These cells (fig. 6, «@) occupied rather more than two spaces 
of the =),,th of an inch, and had in their interior a great 
number of minute clear granules endowed with motion. The 
delicate cell-wall soon burst, and the little transparent gra- 
nules (fig. 6, 6) spread themselves over the field of the micro- 
scope, and moved slowly amongst each other. About four 
of these bodies in a row traversed a space of the ;,,th of an 
inch. They were all of equal size and perfectly round. 
The space of the embryo not already indicated was filled, 
as shown in the figure, with small cells and granules, some of 
which—detached—are drawn in fig. 7. Two pale tubes (m 
m), apparently the excretory of Dr. Cobbold, or the urinary of 
Van Beneden,* curved backwards from the oral sucker, and 
became indistinct in the region of the alimentary ceca. One 
half of the body, from the small end downwards, was covered 
with minute spikes, which were largest in the neighbourhood 
of the sucker. The spikes projected downwards, 7. e. towards 
the swollen end of the animal, and hence the readiness with 
which they entangled the embryo in its exit from the ovum, 
as before mentioned. A portion of the investing membrane 
with these bodies is shown in fig. 8, x 280 diam. 
A similar ovum, and contained embryo, occurs in the liver 
of Cancer pagurus, but much more sparingly. The case is 
somewhat tougher, and the embryo seems to have a closer 
rasp-arrangement of spikes. None were found in an adult 
female Lobster, but an extended examination might prove 
more successful. 
There are various ways by which the ova might have been 
introduced into the above-mentioned sites, and it would be 
interesting to ascertain if the mussels, of which the C. menas 
is so fond, are connected therewith. It is a curious fact that 
the embryo seemed nearly of the same age in every specimen, 
and that no other form of this species was met with. In all 
probability it attains little further development in the body of 
the crab, but awaits the ingestion and digestion of the Crus- 
tacean by such fishes as the Cotti, Gadi, and others, in whose 
* Cobbold, ‘ Entozoa,” p. 26. 
