On Melanenchytraeus Solifugus 



An Oligochaetous Annelid of the family of the Enchytraeidae. 



By CARLO EMERY 



In his expedition to Mount St. Elias, J. C Russell observed on the 

 Malaspina Glacier numerous specimens of a small black worm, which "literally 

 covered " the snow before the rise of the sun, and disappeared beneath the 

 snow as soon as they felt the warmth of the sun rays.^ Russell states that he 

 never found these worms when the temperature was above freezing point. 



The same worms were found again and for the first time collected by 

 Dr. De Filippi, in the conditions described by Russell. They appeared at 

 morning and evening ; on foggy days they disappeared later in the morning 

 and re-appeared earlier before sunset ; but they were never seen in the hours 

 near mid-day. During the sunny hours, Dr. De Filippi tried digging under 

 the snow to a depth of about fifty centimetres without finding any. In con- 

 tradiction to Russell's statement, he observed these worms also when the 

 temperature was above freezing point ; but during the return journey they 

 were much less numerous, and only on those spots of the glacier which were 

 covered with snow. 



The specimens which I have used for this study were put directly in 

 strong alcohol, and are therefore somewhat shrunken ; but the state of preser- 

 vation of the tissues would have allowed a more complete study of the 

 structure of this animal, had the specimens been more numerous,^ and collected 

 at a more advanced season. 



Most of these specimens were immature ; they had not developed sperm- 

 ducts or sperm-sacs or spermathecae. In the more mature specimens, the 

 eggs were minute, and I could not recognise any vestige of female genital 

 ducts ; but one showed a beginning of clitellum development. With few 

 exceptions they were lacking in the organs which are the most important for 

 the discrimination of genera and the determination of affinities in this order 

 of Annelides. 



The worm preserved in spirits (Fig. i) is dark-brown, nearly black. 



^ Secofid Expedition to Mount St. Elias, Washington, 1894, p. 33. Wright {The Ice 

 Age of North America, London, 1890, p. 44) mentions also worms found on a glacier of 

 Alaska and properly on Muir Glacier, " in shallower inclosures of the surface, containing 

 water and a little dirt." The conditions in which they were observed, very different from 

 those in which the worm detected by Russell lives, lead me to think that our worm is not 

 identical to the Melanenchytraeus of the Malaspina, but belongs to a different species. 



'^ The number of specimens would have been greater, had not a part of the collected 

 material been lost by accident.- 



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