74 PACHYMENIA ABYSSORUM. 



of Plate 39, figs. 1, 6. The walls of this division are provided with numerous 

 muscle bundles of irregular distribution between which are multitudes of glands 

 staining actively when treated with Delafield's haematoxylin. The cells com- 

 posing these glands are without distinct cell boundaries, are made up of vacuo- 

 lated protoplasm containing droplets of various sizes and are grouped into 

 lobules of various bulk. In many places they extend into the folds of the epi- 

 thelial lining of the pharynx and give evidence of opening through intercellular 

 channels. 



Some distance toward the dorsal side of the animal a fold of large size ap- 

 pears in the wall of the digestive tract which narrows the pharyngeal cavity to a 

 relatively small tube. At this point the epithelial lining becomes thicker, a char- 

 acter which it retains to the stomach-intestine, and the walls become surrounded 

 by a heavy sheath of circular muscles to which vast number of gland cells attach. 

 These gland cells are grouped into slender lobules, and owing to the fact that they 

 ai'e much vacuolated their tint is fainter than in the case of those of the pre- 

 ceding division of the tract. The nuclei also are of larger size and more distinct, 

 but the secretion presents the same general appearance. A slender duct on 

 each side of the pharynx (Plate 40, fig. 6) extends from the region of the ventral 

 labio-buccal commissure (Plate 39, fig. 8), to its outlet (Plate 39, fig. G). Poste- 

 riorly each ends blindly and anteriorly is provided, as in the case of Alexandro- 

 menia, with a papilla which is doubtless capable of being protruded into the 

 pharyngeal cavity. Throughout its entire extent the ductules from these glands 

 attach to the canal, but behind it they connect with intercellular channels and 

 so pour their secretion directly into the pharyngeal cavity. The glands with 

 this last named outlet present the same appearance as those communicating 

 with the ducts except in the neighborhood of the stomach-intestine where they 

 become more compact. 



No trace of a radula or radula sac exists. 



The pharynx or oesophagus projects for a great distance into the stomach- 

 intestine which is provided with several longitudinal lidges instead of the cus- 

 tomary sacculations. The middle portion of the body was not sectioned but 

 as these ridges are present in the posterior end of the animal it is probable that 

 they extend throughout the entire length of the gut. Many of these folds 

 contain blood sinuses which often produce a marked distention. The lining 

 epithelium is composed of more than usually slender cells many of which con- 

 tain more or less spherical, granular masses. Posteriorly the intestine narrows, 

 passes between the coelomoducts and opens into the cloacal chamber. No 



