The rumen is raised.
]
The =muscular coat of the abomasum= consists of longitudinal and
circular layers; the latter forms a well-developed pyloric sphincter.
The =mucous membrane= of the first three divisions is destitute of
glands, and is covered with a thick, stratified, squamous epithelium;
the superficial part of the latter is horny, and is shed in large
patches in the rumen and omasum. The =corium= (Tunica propria) is
papillated. The mucous membrane of the abomasum is glandular, and
corresponds to that of the right sac of the stomach of the horse. The
short fundus glands occur in that part which presents the large folds,
while the long pyloric glands are found in the remainder, except about
the omaso-abomasal orifice, where cardiac glands occur. The mucosa of
the fundus gland region is very thin as compared with that of the horse.
There is a round prominence on the pyloric valve.