289 



Revue des Sciences Naturelles fondée a Montpellier par E. Dubrueil, publiée 



sous la dir. de E. Plancho n , P. deRouville, A. Saba tier. 3. Sér. 



T. 4. No. 2.' Montpellier & Paris (Dec. 1884.) 1885. 8". 

 Sitzungsberichte der Naturforscher -Gresellschaft bei der Universität Dorpat, red. 



V. G. Dragendorff. 7. Bd. 1. Hft. 1884. Dorpat, (Leipzig, K. F. 



Köhler in Comm.i . ISSF). 8^. (2.58 p.) Ji 2, — . 

 Bitzungs-Berichte der physikalisch-medicinischen Gesellschaft zu Würzburg. 



Jahrg. 1885. Würzburg, Stahel, 1885. 8^ Jl \,—. 



II. Wissenschaftliche Mittheilungen. 



1. Note on the nephridia of a species of Acanthodrilus. 



By F. E. Beddard, M. A., Prosector to the Zoological Society uf London. 



eingeg. 19. Februar 188.5. 



One of the strongest pieces of evidence in favour of Prof Lan- 

 k ester's hypothesis, that earthAA^orrns possess typically two pairs of 

 nephridia in each segment of the body, is afforded by the anatomical 

 characters of the genus Plutellus\ in this earthworm M. Per ri er has de- 

 scribed ' an alternation in the position of the nephridia of each segment ; 

 in one segment they open near to one of the dorsal and in another 

 near to one of the ventral pair of setae : such a fact is best to be ex- 

 plained by supposing the existence of two series of nephridia on each 

 side of the body developed in connection Avith each of the two pairs of 

 setae, both of which series have been partially aborted in Plutelltis\ in 

 certain other earthworms [Lumhricus] the ventral series of nephridia 

 only is fully developed, the dorsal being represented in the genital 

 segment alone by the spermathecae and genital ducts ; in Aniens on the 

 contrary as Mr. Perrier has shown it is the dorsal series of nephridia 

 Avhich has persisted. In Plutellus tAvo out of the four pairs of sperma- 

 thecae open just in front of the nephridia of their segments by the 

 same pair of setae and accordingly M. Perrier is disinclined to allow 

 any homology between the spermathecae and the nephridia though he is 

 of opinion (or Avas in the paper relating to Plutelluü, that the vasa de- 

 ferentia may possibly be the much modified equivalents of tAvo out of 

 the four pairs of nephridia belonging to their segments. 



If the structural peculiarities of a species of Acanthodrilus, which 

 I have lately received from Ncav Zealand through the kindness of Prof. 

 Parker, had been recorded before those of P/w^e/fe* the hypothesis 

 ofLankester Avould have been regarded as almost proved; for in this 



' Arch, de Zool. Expérim. T. 2. p. 245. 



11*^ 



