96 DR. W. C. M'INTOSH ON THE HAIRS OF CARCINUS MENAS. 
compressed, it breaks into many small masses presenting a somewhat radiated arrange- 
ment, and which show the silky aspect even better than before. Under a high power these 
masses are seen to be made up of a vast multitude of hairs of great delicacy, fusiform and 
tapering to an almost invisible point at either extremity (Pl. XX. fig. 5). A peculiar 
feature, however, is that they are almost always bent at a right angle in the middle of 
the spindle,—an arrangement which, in a bunch, greatly complicates the appearance. 
There is a slight central marking in the widest or middle portion ; and, so far as could 
be observed, many have no connexion with a basement-membrane. Nitric acid rendered 
them yellow; and on the addition of caustic potash they became more distinct. Many, 
from their extreme delicacy, are often much contorted. On the intestinal surface, d, is a 
delicate and transparent membrane, having very minute hairs connected with it. These 
hairs are shorter than the deeper ones, and appear to be connected with the membrane; 
yet they are continued beyond it in the shape of pale, delicate processes. At the com- 
mencement of the dotted line, d, in the same figure, is an oblique red band, which slants 
across the internal surface of this part. It (the latter) is somewhat of a similar structure 
with the other portions, and has many of the minute hairs or fibres connected with it; 
but there are a greater number of minute round granules on its surface, which are easily 
detached. 
It will be seen that the posterior region of the stomach has its channel well guarded. 
The wedge-shaped ridge, û, occupies the floor of the cavity and projects upwards, whilst 
the flat, tongue-shaped body blocks the way almost entirely behind, reaching with its 
hairs the superior angle; and, in addition, the canal is further narrowed by the bulging 
of the portion, d, on each side; all which renders the passage of the nutrient matters 
from the stomach to the intestine a complex process. With such an elaborate and 
beautiful structure, one cannot but suppose that these parts play an important feature in 
digestion. ! 
The intestine, from the stomach to the anus, has no hairs. For a considerable extent 
of its latter portion, it is thrown into longitudinal plaits or folds, the intervening spaces 
being pale. The folds are variegated with brownish pigment-masses, apparently from 
an accumulation of basement-structure. The whole membrane has a cellular aspect, 
like a very faint and delicate repetition of the external investment (areolar or cellular 
layer) of the animal; this is especially evident at the middle portion and at the anus. 
Besides these markings, there are groups of boldly-marked cells scattered here and there 
over its internal surface, many being arranged in longitudinal rows. 
Surrounding the anus externally are small hairs with short spikes and serrated 
tips. Fringing the abdominal margin in the males are many very short, branched hairs, 
frequently abraded in the hard state of the Crab. On the under surface of the same 
region are some long, branched hairs. On the great clasper, m, fig. 8, feathered hairs 
our on the base; further up are a number of short teeth, appearing first on the con- 
cave side and then on the other, as well as on the general surface (Pl. XIX. fig. 16). 
They are continued to the tip, diminishing gradually in size, and slope in a contrary 
direction to the course of the limb. At the base of the smaller organ, o, fig. 8, inserted 
into this one are many finely-branched hairs. Just before the organ forks at the tip 
