352 MR. F. E. BKDDARD ON [May 3, 



called it — evidently by a slip of the pen — " Molosoma lacteum.^' 

 I have lately examined a single specimen of an Molosoma which I 

 refer to this species. Unfortunately I am not able to fix its locality 

 with accuracy, as I found it in a bottle containing water and weeds 

 from various sources. 



Leydig himself was of opinion that the species might turn out on 

 further study to be an immature stage of ^. hemprichii, or of 

 some species with coloured oil-drops in the integument ; but he 

 quoted, as against this possibility, Ehrenberg's observation that the 

 red colour is visible in embryos still within the egg, and was there- 

 fore, on the whole, inclined to regard the worm as an adult form of 

 a species with a colourless integument. 



I have, however, recently pointed out that ^ the supposed cocoons 

 are in all probability merely cysts into which the worms can tem- 

 porarily withdraw themselves ; so that Leydig's opinion as to the 

 possibility of his Molosoma niveum being an immature form is not 

 necessarily rendered untenable by Ehrenberg's observations. 



Vejdovsky ^ in describing briefly the characters of his new species, 

 Molosoma variegatum, remarked that it was " hochst wahrscheinlich 

 von Leydig beobachtet und als Molosoma niveum beschrieben." 

 In a fuller account ^ of ^. variegatum Vejdovsky establishes its 

 distinctness from Molosoma niveum ; it agrees, however, with that 

 form in possessing some colourless oil-globules in the epidermis, the 

 rest being green. In JEolosoma niveum all the integumental oil- 

 globules are colourless. 



The most recent remarks upon Leydig's Molosoma niveum known 

 to rae are to be found in Vaillant's account of the Oligochseta in the 

 ' Suites a Buffon.' In that work Vaillant considers it to be not yet 

 established that the supposed species is not the young form of some 

 other Molosoma. I am therefore particularly glad to be able, 

 I think, to definitely settle this question. 



I had on the same slide and under examination at the same time 

 no less than three species of -^o/o«om« — an experience which is not, 

 I imagine, very common. These species were, M. quaternarium, 

 JE. niveum., and a species of whose identity I am not quite certain ; 

 it was as large as my Molosoma headleyi *, but may be Molosoma 

 variegatum; I lost sight of it before I completed the examination. 

 The worm which I believe to be Molosoma niveum is at any rate 

 a perfectly distinct species from any known to me. It comes nearest 

 to Molosoma niveum as described by Leydig. Nevertheless, it does 

 not altogether agree with his description. It may therefore con- 

 ceivably be a new form. It was luUy as large as M. quaternarium, 

 and there are other reasons for believing that it cannot be the young 

 of that, or indeed of any other known species. 



1 " Note upon the Encystment of Molosoma," Ajin. Mag. Nat. Hist,, Jan. 

 1892. 



^ System und Morph. d. Oligochaeten : Prag, 1884, p. 113 footnote. 



^ "Molosoma variegatum, Yejd., Prispevek kii pozhani nejnizsich Annulatuv," 

 SB. bohm. Ges. 1885. 



* "Observations upon an Annelid of khe Genns Molosoma," P. Z. S. 1886, 

 p. 213. 



