1888 - 89 .] Woodhead and Gray on Stomach of Narwhal. 795 
may be traced downwards into the cavity of the first compartment, 
where, however, their character becomes more complex, and they 
present a very remarkable appearance. At first they are elevated 
into crests, afterwards they are broken up into rows of nipple- 
like processes (fig. 1), which gradually get lower and converging 
towards the apical end of the appendage, finally disappear. They 
Fig. 1. 
are exceedingly numerous round the orifice leading to the first true 
digestive cavity, which they may assist in occluding, or at least 
they may act in preventing the passage of large morsels of food 
through it. 
Throughout the first compartment the mucous membrane presents 
a somewhat honeycombed appearance, due to the presence of small 
blind depressions which are most numerous in the nipple-like pro- 
cesses mentioned. 
Structure of Coats. — 1. The outer coat, continuous with the peri- 
toneum, consists of dense areolar tissue with numerous blood-vessels 
and some yellow elastic fibres. The structure of this coat is similar 
to that in the walls of the other compartments. ' 
2. The muscular coat consists of two layers arranged as in the 
