CALIFORNIA EUDRXLID/K. 27 



than the circular muscular laj'or, 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 Luml)ricus, 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 tlie setal 

 grooves, though there are also fdircs between the sette. In the center, between 

 these grooves, the layer is thickest, from there gradually tapering towards the sette. 

 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 bodv. 



A/uncnfnri/ cnrial (fig. 1). The l«iccal cavity is everslble to a remarkable de- 

 gree, so much so that it i.'^ often projected like a large sac 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, iii, but is only dorsally developed. It is much and irregularly foliled, tlie 

 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 (fig'i). 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 viii. 



(KKophnrjus commences between iii and iv, extending backward to somite xvi, 

 being slightly differentiated in xiv, xv, and part of xvi, as a tubular intestine (fig. 1). 

 ffisoi)hagus is much sacculateil, first rising upward and forming a sigmoid jilexus in 

 somite vii, after which it lowers itself somewhat in viii and then extends grachially 

 backward to the sacculated intestine, at the same time gradually diminishing in size. 

 The tubular part in xv or between xv and xvi is the narrowest part of the oesophagus. 

 The glandular epithelium of the (jesophagus is very 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, fig. 1, .s. i., commences in xvi, is generally about four or 

 live times wider than the tubular intestine. It does not increase gradually, but at 



