1114 DR. J. STEPHEKSON ON^ THE OLIGOCHyl'rrA OF THE 



(2) In tlie genus Henlea there are often found other organs, 

 situated in the middle line, one dorsally and one ventrally on 

 the oesophagus, in segm, vi., sometimes extending forwards into 

 v., and backwards behind vi. for, it may be, several segments. 

 The association witli the Avail of the alimentary tube is here much 

 more intimate than in the case of the former structures ; these 

 are closely apposed to the wall of the tesophagus for the whole or 

 the greater part of their extent; they may even be contained for 

 a considerable part of their extent within the wall, between the 

 epithelial and muscular coats (Welch, in H. moderata (19), which 

 I can confirm in H. brucel and H. lieleotroplius). They frequently 

 give branches. 



While the former structures have little about them that can 

 remind the observer of nephridia, these have much more the 

 appearance of the peculiar type of nephridium found in the 

 Enchytraeidse — a spongy-looking, scarcely staining tissue, with 

 nuclei but no visible cell-limits ; sometimes there seems to be no 

 lumen in the interior — nothing more than the interstices of the 

 spongy cell-substance, sometimes there are irregular spaces and 

 tubular cavities, and sometimes a single well-defined central 

 lumen. They have, however, no ciliated funnel or any kind of 

 internal opening. Cejka, in the worms which he called Hepato- 

 gas'ter, states (3) that there are indications of the double origin of 

 these apparently single and median structures ; in this I agree 

 (compare the transverse section of a ventral organ of U. brucei, 

 fig. 1 ; the description of the ventral organ in Henlea sp. (l),j}ost., 

 and of the dorsal organ in H. heleotrophus, where possibly there 

 is no connection between the masses on the right and left sides) ; 

 while Welch finds that in H. oohracea (22) the organs are actually 

 paired, one pair dorsally and one pair ventrally. It is, perhaps, 

 this rype of gland which is intended by Friend in his reference 

 to the salivai'y glands of H. alba (7) and R. inusitata (8), and to 

 the "special glands" of H. bisetosa (8). 



(3) There is a third type of organ, which is apparently widely 

 spread in the family. Descriptions of these structures are given 

 for all the newly described species beiow, and they also occur in 

 the Menenchytrceus ; I have described and illustrated similar 

 structures in the Iiidian worms EnchyircBus barhudensis (14, and 

 see also pi. vi. fig. 1 in 15) and in Fridericia carmichaeli (15). 

 Briefly, these orga,ns consist of a pair of rounded, or ovoid and 

 bulb-like, masses of ceils, solid, situated behind the pharyngeal 

 mass on the dorsal side of the alimentary tube, and connected 

 with the tube by a stalk, which is at any rate partly solid, but is 

 usually hollow in its proximal portion — -i.e., the cavity of the 

 alimentary tube may penetrate the basal portion of the stalk. 

 U"de probably had this type of organ before him when he described 

 the rudimentary salivary glands of Bryodrilus ehlersi (16), two 

 ijmall pear-shaped bodies, in which no lumen could be recognized 

 immediately behind the pharynx ; and, indeed, since I first met 

 with these structures some years ago, I believe I have myself 



