52 MR. F. E. BEDDARD ON jEOLOSOMA TENEBRARUM. [Feb. 5, 



Soc. 1888, p. 213). I am also able to take this opportunity of 

 anuounciug the occurrence in Ireland of Vejdovsky's species JEolo- 

 sonia varieyatum (" jEolosoma variegatum, Prispevek ku poznaui 

 uejnizsich Anuulatuv," SB. bohm. Ges. Wiss. 1885), of which some 

 examples were kindly forwarded to me by Prof. Howes, who had 

 himself received them from Prof. Hartog, of Cork. A comparison 

 of JE. tenebrarum with JE. variegatum has convinced me that, as I 

 stated in my paper, the affinities of M. headleyi are with the latter 

 species. In both these forms the epidermic coloured cells are bright 

 green, while in ^. tenebrarum they range from greenish yellow to 

 brownish olive, j^. tenebrarum, furthermore, difl'ers from all other 

 species of the genus in possessing (-shaped setae in the posterior 

 segments of the body, in addition to the hair setae present in those 

 segments and elsewhere : the setae are stated by Vejdovsky {loc. cit.) 

 to be bifid at the free extremity, but I have not been able to see this 

 in my specimens ; in Vejdovsky's specimens the epidermic coloured 

 cells are of a pale yellow, contrasting therefore with the specimens 

 studied by myselfj which I am unwilling, however, to refer to a new 

 species since they agree in all other particulars with ^'E. tenebrarum. 



This species of Molosoma is extremely hardy if supplied with 

 sufficient food. I have a large number of specimens which go on 

 multiplying rapidly in a small bottle containing duckweed and a thin 

 layer of vegetable debris at the bottom ; the worms have remained 

 in this small vessel for several months, although there is a tolerably 

 thick scum of Leptotkrix and Bacilli upon the surface. 



On the other hand, if deprived of food they soon die ; three 

 specimens placed in a watch-glass containing water from the vessel in 

 which they lived, but no appreciable quantity of vegetable debris, 

 died in an hour and a half. The watch-glass was placed on a 

 window-sill of north aspect. In these particulars JE. tenebrarum 

 contrasts with jE. variegatum. I placed the specimens of the latter 

 species in a bottle with abundant food ; the water and the duckweed 

 were obtained from a locality where there were no specimens of 

 ^. tenebrarum ; one or two examples of the latter were, however, 

 introduced by means of a pipette ; these multiplied to a great 

 extent, and I have not been able since to discover a single specimen 

 of JE. variegatum. 



The green-coloured spots of jE. tenebrarum are large cells with a 

 thin peripheral layer of protoplasm containing a nucleus ; in the 

 centre is a large globule of oily appearance impregnated with the 

 colouring-matter. Vejdovsky has remarked {loc. cit. p. 65) that 

 the globule is stained black with osmic acid, thus proving it to be 

 of an oily nature. I have found that osmic acid produces a dark 

 brown stain. 



The green colouring-matter naturally suggests chlorophyll ; and 

 Zacharias (" Studien iiber die Fauna des grossen und kleineu Teiches 

 im Riesengebirge," Zeitschr. wiss. Zool. Bd. xli. pp. 499-500) states 

 that in an ^Eolosoma (probably .^. variegatum) he observed the 

 green bodies dividing, and therefore considers that they may be 

 parasitic algae. "With a view to discovering whether the bodies 



