336 OLIGOCHAETA 



n. Brain convex behind or but slightly concave. 



i. Funnel of sperm-duct very long E. humicultor. 



ii. Funnel short : 



(i) Spermathecae almost sessile E. adriaticus. 



(2) Spermathecae with longish duct: 



(a) Preseptal part of nephridium with straight duct. 



Duct of spermatheca dilated E. hyalinus. 



No such dilatation E. buchholzii. 



(b) Preseptal part of nephridium with a convolute 



duct . . . . E. argenteus. 



It will be observed that I omit Levinsen's E. affinis, which is admitted by Michaelsen. This 

 species (termed E. danicus by Vaillant, on the ground of the pre-occupation of the name 'affinis' by 

 Eisen) is only mentioned by MlCHAEtSESf in his Revision to distinguish it on account of its coloured 

 blood. It does not seem to me that Michaelsen is justified by the extremely slender description 

 given by Levinsen in referring this species to the genus Enchytraeus (s. s.) ; no doubt, there is nothing 

 in the description which positively forbids this identification ; the species, in all probability is referable 

 either to this genus or to Fridericia ; but why not to the latter ? Levinsen does not mention the 

 dorsal pores, but neither does he in the case of ^Enchytraeus' bisetosus, placed by Michaelsen in the 

 genus Fridericia. The most remarkable fact about the species is the presence of 'chlorophyll 

 corpuscles' in the integument. Concerning these further information is to be desired. 



'Enchytraeus' minut'us of Tauber may or may not belong to this genus. It is not referred to 

 by Michaelsen. It is, if an Enchytraeid, the minutest species, measuring only o-i mm.; the 

 setae are paired (cf. Fridericia iisetosa) : ' Semen vivum in segmento quai-to, ova in quinto sextoque.' 

 This does not seem intelligible on the theory that the worm is of this family. 



(i) Enchytraeus humicultor, Vejdovsky. 



Enchytraeus humicultor, Vejdovsky, Ench., 1879, p. 57. 



E. spiculus, MoBius, JB. Comm. wiss. Unt. deutsch. Meer., 1873, P- i°7 (™ part.). 



Neoenehytraeus vejdovskii, Eisen, Ofv. Svensk. Akad., 1878, No. 3, p. 75. 



N. Stuxbergi, Eisen, ibid., p. 75. 



Pachydrilus lacteus, Taubee, Ann. Dan., 1879, P- 7i- 



E. fucorum, Levinsen, Vid. Med., 1883, p. 235. 



E. sordidus, Levinsen, ibid., p. 235. 



E. vejdovskii, Vejdovsky, Syst. u. Morph., 1884, p. 41. 



E. Stuxbergi, Vejdovsky, ibid., p. 41. 



Archienchsrtraeus mbbii, Michaelsen, Zool. Anz., 1885, p. 237. 



E. mobii, Michaelsen, Ench. Mob., 1886, p. 1 1. 



' To the above list of synonyms should possibly be added E. vermimlaris of Taueek (^in part.), which 

 Levinsen identifies with his E. sordidus. 



