SEA-FISHERIES LABORATORY. 207 
intestinal division of the straight intestine. Their maxi- 
mum length is about 0°2 mm. They are finely granular, 
with the nucleus at any level from near the free extremity 
to near the bottom of the cell. “They bear a covering of 
very short cilia. Sometimes, at the middle of the free 
surface, there is a little groove in which the cilia are 
matted together. This is not constantly present, and it 
is probably due to the action of reagents. 
The epithelium, of the intestinal portion especially, rests 
on a layer of dense connective tissue, which fills up the 
spaces between the epithelia forming the anterior and 
posterior folds, and is found in patches all round the 
intestine. This presents no very obvious structure. It 
seems to be largely fibrous, with nuclei scattered through 
it. It stains densely with haematoxylin. It includes 
large irregular spaces, evidently blood channels; in its 
substance are seen corpuscles of various kinds, blood 
corpuscles and corpuscles containing a greenish substance. 
The crystalline style (St., fig. 12, Pl. ITI.) completely 
fills the lumen of the left division of the straight portion 
of the gut. In sections made from hardened specimens, 
the style is usually seen to be retracted away from the 
wall of the sheath. But since, in such preparations, it 
may be observed that the superficial layer of the ciliated 
epithelium is in some parts torn away and adherent to the 
substance of the style, it is evident that this contracted 
condition is due to the process of embedding; and the 
same cause most probably gives rise to cavities sometimes 
observed in its marginal part. In hand sections of the 
animal, simply killed with formol and examined under a 
low magnification, the style appears perfectly homogen- 
eous, and completely fills the sac. 
No obvious structure is to be observed in the style 
except a very delicate concentric lamination. It is per- 
