238 University of California Publications. [ ZooLocy 
a cirelet of tentacles (tent.) around one extremity. Various 
regions of the tubular portion have specific names. In 
the middle of the membranous floor from which the tentacles 
arise is the mouth (m.). This opens into a short tube known 
Fig. 1—Beania mirabilis. A zowcium and its inclosed polypide shown in 
profile view. c. sp. crossed spines; car. val. cardiac valve; é. sp. 
erect spine; i. intestine; m. mouth; @s. wsophagus; or. orifice; 
par. mus. parietal muscle fibres; pd. polypide; ph. pharynx; 
py. val. pyloric valve; r. f. root fibre; re. mus. retractor muscle; 
st. stomach; tent. tentacles; tent. sh. tentacle-sheath; 2a. 
zoccium. 
as the pharynx (ph.) which is really a portion of the cesophagus 
(ws.); this in turn opens by a narrow valve, the cardiac valve 
(car. val.) into a stomach (st.). The stomach is a bag of a 
yellow or brown color due to the gland cells in its walls; it opens 
into the intestine (7.), by the so-called pyloric valve (py. val.). 
Visible above the tentacles when the polypide is retracted is a 
delicate membrane, the tentacle-sheath (tent. sh.). Near the 
distal end where the tentacle-sheath approaches the orifice (or.), 
a few muscle fibres may be seen on each side of the sheath ex- 
tending to the walls of the zowcium. These are part of the 
parieto-vaginal muscles which assist in retracting the tentacular 
