92 DR. W. C. M'INTOSH ON THE HAIRS OF CARCINUS MANAS. 
Hairs of Branchie.—Along the tough membrane forming the boundary of the inferior 
canal of each branchial tuft is a double row of short simple hairs. They present what 
appears to be a large rounded bulb, with a strong, slightly curved shaft. In the soft 
Crab there are occasionally some small ones at the beginning or base of the rows, but 
generally they diminish in size towards the tip. In Pl. XX. fig. 15 is sketched a hair 
from this region, with the brownish bulb, which has apparently been ruptured. The 
cellular or areolar nature of the cutis gives this the fictitious aspect of being filled with 
nucleated cells. Upon the hairs are several parasitic structures, algee, fungi, &c. In 
Pl. XX. fig. 14 is shown the tip of a hair from the branchial row of a Crab (kept for nine 
days in a vasculum), with a parasitic tuft attached. On the bases of the hairs and the 
surrounding textures a curious parasite presented itself in the shape of a pale zoophyte, 
which spread its stems from hair to hair after the manner of a creeping rhizome, and 
shooting up beautiful branches ever and anon, with their living freight. Floating about, 
too, were many loose bodies of an ovoid or flask shape, which were probably stages in the 
development of the animal, and which appeared to be furnished with cilia. The outline 
of one, highly magnified, is given in Pl. XX. fig.17. In some specimens of the zoophyte 
there were fine hairs connected with the terminal portion of each bud, as shown in that 
sketched on the hair in Pl. XX. fig. 15. An enlarged view of a portion of the animal 
is given in Pl. XX. fig. 16. It occurred in numerous specimens of the Crab, and lived 
with it in captivity for many days. 
Gisophagus and Stomach.—There may be said to be no hairs in the cesophagus; for 
although there are some just at its termination, these may be regarded rather as hairs of 
the stomach than of the cesophagus. The membrane throughout is granular, more 
so at some parts than others, and a few cells are scattered here 
and there. The presence of hairs in the stomachs of these ani- 
mals shows of how much importance these structures are in 
Crustaeean economy, as well as demonstrates the homology be- 
tween the lining membrane of the stomach and the external 
investment. A portion (a, fig. 9, enclosed within the dotted 
lines) taken from the upper wall of the stomach was found to be 
covered, on its internal surface, with minute translucent hairs : 
with slight serrations; a few of the larger ones are sketched in Pl. XX. fig. 1. Some are 
of considerable length, and others quite short, broken off near their insertion. Generally 
speaking, the surface in front of the transverse dotted line, û c, has hairs on the anterior 
and lateral curvatures, with a few in the centre. At the bend in front of the cesophagus 
are a number of the same kind of hairs. On the under surface of the stomach, at the 
anterior portion, the hairs are scant on the outer parts, aa, fig. 10, but increase in number 
towards the middle line. A portion cut from b showed the hairs greatly increased in 
number, and having scattered amongst them, on the wall of the stomach, a great number 
of little cellular bodies, which, with the hairs, are seen in Pl. XX. fig. 6. ‘These bodies 
were generally of an irregular shape, somewhat resembling starch-granules in aspect; 
but nuclei or analogous internal markings were distinct in most. The ridges, c c, which 
overlap the central smooth depression are fringed with closely-set hairs (Pl. XX. fig. 2)- 
Fig. 9. 
