CATTIFORNIA EUDRILIDA, 
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than the circular muscular layer, and this again is thinner than the longitudinal 
muscular layer. The clitellum is perfect, but somewhat thicker on the upper part. 
The glandular layer is very thick, being about ten times thicker than the two mus- 
cular layers combined. The longitudinal fibres are nowhere arranged in such 
feather-like: bunches as in Lumbricus, but much more irregular, with a faint ten- 
dency to feather-like bunching. This is the rule both in the clitellum and elsewhere. 
This stratum of longitudinal fibres is, as usual, interrupted in four places by the setal 
grooves, though there are also fibres between the sete. In the center, between 
these grooves, the layer is thickest, from there gradually tapering towards the setie. 
The under side, or the ventral part, of the layer is somewhat thicker than the dorsal 
part. 
The clitellar glands are less regularly paired than in Lumbricus though 
the general arrangement is that of two or three rows of glandular cells together. The 
clitellum is very thick and developed all around the body. 
Alimentary canal (fig. 1). The buceal cavity is eversible to a remarkable de- 
gree, so much so that it is often projected like a large sae or bladder, covering more 
or less perfectly the prostomium and part of the peristomium. Its walls are very 
thin and transparent. The pharynx commences with the prostomium and covers 
somites i, ii, iil, but is only dorsally developed. It is much and irregularly folded, the 
sinuses being sac-like and not parallel, the largest ones being in somites ii and iii. 
The muscles of the pharnyx are thickly covered with salivary glands. Superiorly 
these glands project along the under side of the muscular bands, which extend back- 
ward, thus forming three rows of parallel projections tapering from base to apex. ‘The 
anterior of these salivary glandular masses is the largest, the third, or the most posterior 
one, the shortest (fig6). The posterior half of the salivary glandular mass forms one 
single projection equal to all the anterior ones together. This gland is connected with 
and partially rests on two muscular bands attached to the body-wall between somites 
vii and yiil. 
(Hsophagus commences between ii and iy, extending backward to somite xvi, 
being slightly differentiated in xiv, xv, and part of xvi, as a tubular intestine (fig. 1). 
(Esophagus is much sacculated, first rising upward and forming a sigmoid plexus in 
somite vii, after which it lowers itself somewhat in viii and then extends gradually 
backward to the sacculated intestine, at the same time gradually diminishing in size. 
The tubular part in xv or between xy and xvi is the narrowest part of the cesophagus. 
The glandular epithelium of the cesophagus is yery narrow in the anterior somites, or 
those in front of the clitellum, and the blood sinuses in them are narrow. In the 
anterior part of the clitellum the epithelial villi become greatly elongated with in- 
creased blood supply, while in the central part of the clitellum these blood sinuses be- 
come very large, occupying the largest part of the epithelial lobes. The nuclei in those 
epethelial cells are everywhere round. 
The sacculated intestine, tig. 1, s. i., commences in xvi, is generally about four or 
five times wider than the tubular intestine. It does not increase gradually, but at 
