132 PROCEEDINGS OF THE ACADEMY OF [1899. 



beaumeri Michaelsen ('87) eight times as long. According to- 

 Eisen the relative lengths of ducts and funnels vary greatly within 

 the limits of the single species M. mirabilis Eisen ('79), in some 

 individuals the former being but four times, in others as much as 

 ten times as long as the latter. 



M. solifugus is, however, a very distinct species, whose nearest ally 

 seems to be M. mirabilis Eisen. According to Michaelsen ('87), 

 the latter species has a single sperm and a single ovisac, both of 

 which are greatly elongated caudad and constricted at the septa. 

 It further approaches solifuxjus in the elongation of the sperm ducts. 

 The entrance of a sperm duct into the ovisac has not been de- 

 scribed for any other member of the genus, in which these ducts 

 are usually coiled up Avithin the limits of somite XII. But the 

 relation of the sperm ducts, and particularly of the right one, 

 to the mouth of the ovisac, is such as to permit of ready entrance, 

 and it may in future be found to take this j)osition in some other 

 species. The enlargement of the outer end of the sperm duct and 

 its glandular appendages are better developed in this than in other 

 species. 



With but very few exceptions, the Enchytrieidis are translucent 

 and colorless, or have but very little integumental pigmentation. 

 Very remarkable and distinctive therefore is the thick opaque 

 deposit of pigment granules in the epidermis of this species, and 

 the conditions under which the worm lives make an explanation all 

 the more difficult to find. 



The foregoing description and much that follows were written and 

 the accompanying draAvings prepared in December, 1897. The paper 

 was then laid aside pending some projected experiments designed 

 to determine the physical factors effective in stimulating the pro- 

 duction of pigments in the Oligochfeta. No opportunity for carry- 

 ing out this plan has been found, and in the meantime Prof. Emerv 

 has described the worm in two short papers ('98"^ and '98^ ) under 

 the name Melanenchytneus solifugus from specimens collected on 

 the Malaspina Glacier by Dr. Filippi, of Prince Luigi's party. 

 The description is communicated at the present time at the request 

 of Mr. Bryant. I had called the worm Meseiichytneus nivus, 

 a name which is now discarded, owing to the earlier publication of 

 Emery. 



To the new genus Melanenchytnvus the following characters are 



