62 W. C. MCINTOSH. 
on by the area with the ridges and the powerful muscles 
beneath, so that—between muscles and glands—a considerable 
alteration probably ensues. There are grounds, therefore, for 
thinking that this chamber represents the stomach, since its 
posterior end leads by a short canal directly into the intestine. 
The intestine follows the short canal just mentioned, and 
consists of a wide passage, usually thrown in the preparations 
into deep folds—with a few shallow diverticula of its walls; but, 
so far as spirit-preparations can be relied on, the diverticula 
do not attain the dimensions shown by Ehlers in his HE. race- 
mosa.! The canal has a thick wall of densely granular glan- 
dular tissue, papillose internally, and of circular fibres ex- 
ternally. It continues backward and terminates posteriorly 
in the vent, which is situated between two prominent lips just 
in front of the caudal papille. A differentiation of the gut 
occurs at the rectum, so distinct that in transverse sections it 
appears at first sight that an independent channel exists pos- 
teriorly. The continuity ofthe mucous membrane is, however, 
easily made out. In this region, which is somewhat triangular - 
in transverse section, the thin membranous investment has 
beneath it a layer of longitudinal fibres, and the adjacent 
granular cells more resemble those of the hypoderm than the 
homologous cells of the intestine. Portions of food and sand are 
occasionally observed in the centre of this portion of the canal. 
The food consists in some of a soft mass in which cells, 
spicules of sponges, chitinous fragments, and other débris are 
present ; while in others little else than sponge-spicules can 
be seen. Posteriorly the cylindrical feecal mass usually occu- 
pies the centre of the gut. In Schmarda’s species calcareous 
fragments, bristles of Annelids, and sponge-spicules were 
found. It may readily be concluded, therefore, that it is diffi- 
cult to secure either perfection or continuity in transverse 
sections of the body. 
The digestive system of S pinther differs from the foregoing 
in regard to the much more largely developed lateral ceca of 
the gut, and the less massively muscular proboscis. The 
Op. cit., Taf, ii, fig. 1. 
