DR. W. C. M'INTOSH ON THE HAIRS OF CARCINUS MJENAS. 89 
The elevation at d, and the margin below, have long and beautifully serrated hairs; 
. some having smooth basal portions, others with short and thinly-spread bristles. At f 
there are some branched hairs, but along the rest of this outer or concave margin there 
are no hairs. 
A little to the outer side of the limb here described is a tuft, e, of exceedingly long 
serrated hairs, about half an inch in length, which spring from the slender basal portion 
of the foot-jaw and taper to an extremely delicate point. In the soft Crab they are best 
studied to advantage. Whentorn out, they often show a transverse rupture of the cortical 
portion, from which protrudes backwards a pale mass of the central substance. The 
latter appears to occupy the bulk of the hair at the lower part, and, in the largest hairs, 
proceeding forward, this portion is widened rather than narrowed in proportion to the 
diminished diameter of the hair; in fact, the cortical portion is so insignificant that the 
former appears to occupy nearly the whole breadth of the hair. The marginal portion 
is translucent and structureless, the central granular. In the largest hairs the serrations 
extend only a comparatively short distance behind the tip, and in several there are large 
recurved fangs of the form previously described *. 
Mandibles, tig. 7.—Attached to each powerful mandible is a short jointed limb, which 
bears numerous hairs on its sides. They are often so coated with parasitic structures in 
the usual state of the Crab that it is a somewhat difficult task to make out the exact 
nature of the hair. In the soft Crab it is found that both the concave and convex sides 
have a series of thickly branched hairs, which, like many Fig. 7. 
others in a like condition of the animal, curve exquisitely in 
all directions. "Towards the tip on the concave side, a, fig. 7, 
the branched hairs become serrated at the extremities, then 
follow some only serrated, and finally the tip and part of the 
anterior (convex) margin of the last segment is covered with 
strong bristles, some of which exhibit slight serrations. The 
same rotation follows on the convex side, 5, viz. strong hairs 
merging into more slender, then serrate-branched, and finally 
branched. The general surfaces of the segments have strong 
smooth spikes and feathered hairs, with the exception of a A 
portion of the terminal one, which is bare. j see 
Hairs of the Cephalothorax, $c.—On the under surface, at 4, fig. 8, and in that 
neighbourhood, the hairs are pale, elongated, and most.y spiked with long bristles 
(Pl. XIX. fig. 15). At the ridge, û, they have the same aspect, and are often quite 
covered with extraneous growths. Along the border at €, and continued round behind 
the last limb, are many long, branched hairs arranged in a row. : 'The hairs on all these 
places are alike, longer, more translucent and flexible than usual in the perfect condition 
of the animal. Fringing the scalloped margin, d, of the central islet are strong 
feathered hairs, whose tips occasionally show sharp serrations, like minute bristles. 
Rows of the same, e, e, e, are found in well-marked specimens, extending inwards along 
* Vide p. 87. 
