DR. W. C. M'INTOSH ON THE HAIRS OF CARCINUS MANAS, 85 
on the outer margin are both serrated and feathered; two of these, with a portion of the 
cuticle, are seen in Pl. XIX. fig. 7. The ventral surface has few hairs and few minute 
cuticular spikes. At the basal portion, e, on the inner side, they are of no great size, 
and branched. Some at the upper angle have a tendency to become serrated at the 
tip, as well as branched in other parts. The larger hairs on this portion are of the same 
form, but more boldly serrated at the tip. 
The hairs of the flabelliform appendage of the horny accessory limb pertaining to this 
foot-jaw are most interesting. "They are branched in a very regular manner to the tip, 
have a somewhat jointed aspect (best seen in the recently moulted or in those softened 
by the action of an acid), and have a distinct double outline and a large central space. 
In Pl. XIX. fig. 9 a peculiar ending of the organ is sketched, showing smaller hairs and 
a different aspect generally, probably the effect of injury, since in the normal state it has 
nearly the same appearance as that of the next pair of foot-jaws (Pl. XIX. fig. 10). 
In the process of either foot-jaw it will be observed that the hairs spring both from 
the dark horny portions and the intervening lighter ones, though most of them 
certainly arise from the former by broad joint-like attachments. On the first joint, f, 
of this segment the hairs are of two kinds—very small smooth hairs, shaped like those 
on the nettle, and slightly bristled ones'of larger size, though much less than those 
on the tip. These cover the falciform edge of f. The long horny segment, » has 
its outer margin clothed with short and prettily serrated hairs towards its distal, and 
branched ones at its proximal portion; while its inner edge, having likewise branched 
hairs, possesses, in addition, some serrated at the tip and others quitesmooth. The latter, 
with a few small serrated ones, are also spread over part ofthe general surface. The 
hairs at the tip of the whip, n, are delicately serrated, and have several large, recurved 
fangs, as in the case of the previous foot-jaw ; they are smooth from the base to the 
latter fourth. In other respects they agree with those of the first pair, though more 
slender. It may be mentioned here that these and similar hairs throughout the Crab 
(more especially in the soft condition), when preserved in spirit, have their central 
portion rendered more distinct by being tinged yellow, while the cortical remains pale. 
Third pair of Foot-jaws.—The tip of the accessory organ, a, fig. 3, at the base, has 
rather long and finely serrated hairs; some, however, are so minutely marked that the 
serrations are almost unnoticeable. Along the upper or anterior margin they continue 
serrated, but mingled with others quite smooth from base to extremity. In the angle 
between this and the other limb, رق‎ a few feathered ones are visible. Over its ventral 
surface feathered ones predominate, accompanied by many short simple hairs. On the 
under (dorsal) surface they are chiefly serrated, some being both serrated and branched. 
At the tip of the flattened limb, û, the hairs are pale, pretty strong, and minutely ser- 
rated for more than a third of their terminal length. Under the microscope, one side is 
often seen serrated and the other margined with bristles, probably because that is the 
position in which the hair lies most easily and flatly ; they have, in reality, two rows of 
serrations, with an intervening one of minute bristles, as in the case of the coarser ones 
observed previously. The extremity of one is shown in Pl. XIX. fig.5. The other hairs 
on this portion are of the following nature :—Along the free or oral border they are 
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