276 
SIDNEY F. HAEMEE. 
Rhabdopleura (its homologue). Its anterior portion, which 
forms the posterior boundary of the mouth, is composed of 
very long, ciliated, rod-like ectoderm-cells, with much elongated 
nuclei (figs. 11 and 18). The posterior wall of the epistome 
is formed of large cells, and bounds anteriorly a diverticulum 
from the vestibule. At the bottom of this diverticulum is the 
ganglion. 
The oesophagus communicates with the dorsal and anterior 
end of the stomach, as indicated in fig. 2, the passage of the 
stomach into the intestine being shown in fig. 1 and fig. 11. 
The rectum is separated by a constriction from the intestine ; 
in L. cr as si cauda it protrudes into the vestibule as a large 
cone-like process (fig. 11), whilst in most other species the 
posterior wall of the rectum is closely applied to that of the 
vestibule, so that in these cases there is no free rectal cone. 
The whole of the alimentary canal in L. crassicauda is 
lined by cilia, even the “ liver-cells” of the stomach forming 
no exception to this statement. These cells are nucleated 
peripherally, whilst more centrally they contain yellow 
“ hepatic” spherules, which give their characteristic colour to 
this part of the stomach. 
In L. Leptoclini the stomach is produced laterally into a 
pair of wing-like outgrowths (fig. 2). In some species the 
occurrence of a parasite, a holotrichous Infusorian, swimming 
about in considerable numbers in the stomach, is very constant ; 
three of them are seen in fig. 11 (/). 
Connective Tissue and Muscular System. — These structures 
are best studied in the living animal or in glycerine prepara- 
tions. The whole space between the ectoderm and the ali- 
mentary canal is completely filled, either by the gonads and 
other organs, or by a gelatinous matrix enclosing connective- 
tissue-cells, muscle-cells, &c. 
The Entoprocta possess no body-cavity nor any definite 
system of spaces representing this structure. 1 The gelatinous 
matrix is perfectly transparent and hyaline, and, I believe, 
1 Paired spaces, shown in fig. 11, usually occur in the epistome of L. 
crassicauda. 
