204 OLIGOCHAETA 



that those of M. viridis are. In other respects it must be admitted that the present 

 species comes very near to M. houteni. 



A remarkable point about it is its colour. What this may have been during life 

 I do net know ; but after preservation in alcohol it is dark green above, with a very 

 abrupt demarcation between this and the yellowish of the ventral surface. Benham 

 has commented upon a similar plan of coloration in M. indicus. 



The dorsal vessel showed indications of being double in segment xi, a fact which 

 is also noted by Hoest for M. houteni; the last pair of hearts were in the same 

 segment. 



The thickened septa show the same very peculiar arrangement that appears to 

 characteiize M. houteni; there are a set of thickened septa in the anterior 

 segments, and another set. behind the "gizzards. The septa in question are vii/xi 

 and xix/xxv. The two septa enclosing the thirteenth segment meet laterally, so as 

 to form a closed compartment. 



The sperm-sacs are large and rounded ; they lie in the same segment as that in 

 which the spermiducal glands lie ; they are almost spherical in shape, with a long 

 and narrow neck connecting them with the septum x/xi. The sperm-ducts are not 

 much coiled ; they pass, as has already been described, from the interior of the 

 sperm -sacs to the ventral body- wall, which they perforate, as in M. indicus; 

 but emerge sooner to enter the spermiducal gland. The latter have an appearance 

 like that of the corresponding glands of Diplocardia communis (see below) ; they 

 are marked by rounded spots, which are in reality the masses of glandular cells 

 which form the outer layer of the organ; the gland ends in the body- wall, without 

 undergoing any apparent change in its structure. 



The ovaries are large, and lie in the thirteenth segment; they extend on to the 

 dorsal surface of the gut, and are suggestive rather of a gland connected with the gut 

 than of the ovaries, which a microscopical examination of their contents showed them 

 to be. The egg-sacs are also large, but they do not extend even as far as the 

 posterior wall of the fourteenth segment, to the anterior septum of which they 

 are, of course, attached ; they open by a wide mouth into the cavity of the 

 thirteenth segment, opposite to the ovaries ; projecting from this mouth was 

 a curious structure, having the appearance of a mass of fine tubes, closely branching 

 and anastomosing ; a good deal of the egg-sac itself was also lined with a similar 

 mass of tubes, which are clearly 'blood-vessels ; the closeness and complexity of 

 this tuft of vessels is, possibly, an indication that the egg-sacs have the capacity 

 for growth, and that they may, when the worm is perfectly adult, have the same 

 extent as in M. houteni. 



