DESCRIPTIONS OF GENERA AND SPECIES 215 



figs. 2 a-d), Dalzell (PI. xviii, figs.. 10-12), Buchholtz (fig. 16), Katzel (3, PI. xlii. 

 figs. 6, 10, II, 14, 19), Vejdovsky (24, PI. viii. fig. 68, pi. xii. figs. 16-32), BiJLOw 

 (1, 2), Kandolph (4). 



Genus Rhynchelmis, Hoffmeistek. 



Syn. Euaxes, Gkubb. 

 ? Lyoodrilus, Grdbe. 



DEPiwiTioisr. Setae not bifld at tip ; clitellum VIII-XVI ; prostomium elongate ; testes 

 in IX, X ; ovaries in XI ; sperm-sacs and egg-sacs paired, extending through a large 

 number of segments ; spermiducal glands opening on to X, with a coating of 

 glandular cells broken up into rounded masses ; spermathecae one pair opening 

 on to VIII, each pouch with a single diverticulum ; a single median albumen- 

 gland opens on to IX. 



The name Rhynchelmis is obviously the right one to apply to this genus ; but the synonym 

 Euaxes has persisted for a long time, in spite of the fact that Gkube himself recognized the identity 

 of his Euaxes fiUrostris with Hopfmeistee's (3) Rhynchelmis. d'Udekem (1), for example, has 

 retained the name Euaxes, although he gave correctly the synonymy of the species fiUrostris ; so, too, 

 Clapak^de (2) and Vaillant (3). In his later work (6) Vaillant has set this matter right, 

 pointing out that Geube 'in 1851 preserved his own generic name of 1844, though giving as a synonym 

 Rhynchelmis with the date 1843.' Vaillant (6) considers that Gkube's genus Lycodrilus must also be 

 regarded as a synonym of Rhynchelmis ; this genus was created for a species, L. dyhowskii, from Lake 

 Baikal ; from Geube's account it would appear to differ from Rhynchelmis by the presence of large 

 bifid setae, replacing the setae on the ventral side of the body on segments ii-x. I am disposed, 

 therefore, to agree with Vejdovsky (24) in not referring the worm to the present genus, but to regard 

 it as 'incertae sedis.' Though using the name Lycodrilus as a synonym of Rhynchelmis, Vaillant 

 prefaces the description of the species L. dyhowskii by a query. Our knowledge of the anatomy of this 

 genus dates from the publication of Vejdovsky's important paper upon this worm (5). Neither 

 HOPPMEISTEE nor Geube gave any satisfactory details upon the internal structure ; their memoirs 

 were devoted almost exclusively to the external characters ; when Geube did venture upon aiiy 

 references to structure, they were by no means successful; for example, he mistook the contractile 

 appendages of the dorsal blood-vessel for caeca of the gut, which are non-existent. Some few 

 additional details and figures were given by the same author in his work upon the Oligochaeta (8). The 

 reproductive organs and the development have been recently described by Vejdovsky (24), some of 

 his earlier statements being revised; the only other author who has written upon this genus is 

 Kovalevsky, who investigated its development a good many years before the appearance 

 of Vejdovsky's work upon the same subject. 



The genus Rhynchelinis is, so far as our present knowledge goes, confined to the 



fresh waters of Europe ; it has been met with in Bohemia, Russia, Belgium, and 



Germany ; I point out later that certain species, referred to this genus from other 



parts of the world, are probably not really referable to it. I have seen a specimen 



