DESCRIPTIONS OF GENERA AND SPECIES 247 



In a species of Limnodrllus from New Zealand there are two pairs of dilated 

 hearts in precisely the same segments (viz. viii and ix) as those in which these 

 hearts occur in Glitdlio. This lessens the gap between the two genera. It should, 

 however, be mentioned here that the specimens of Liimnodrilus novae-zelandiae 

 examined by me were sexually immature. It is therefore, perhaps, begging the 

 question to refer them to the genus Limnodrilus, which I do on account of their 

 fresh-water habitat. 



Vaillant (6) enumerates nine species of ClitelUo of which some are apparently not referable to 

 this genus ; ClitelUo henedii is, as is pointed out elsewhere, a Hemituhifex ; Michaelsen (5) assigns 

 ClitelUo linealus to the genus Pachydrilus. I discuss this view below. So, too, ClitelUo minutus. 



ClitelUo inaequalis, described by 0. F. Mtjllee as ' Lumbricus' inaegualis, and doubtfully referred 

 by Geube (8, p. 104) to this genus is a difficult species to come to any conclusion about. All that 

 MtJLLER says about it is — ' Papillis lateralibus simplicibus ; setis solitariis.' Vaillant justly remarks 

 that these characters are 'trop succinctement donnes' to enable any conclusion to be drawn. The 

 papillae obviously suggest Hemitubifex henedii. ^ 



ClitelUo neurosoma of Fkey and Leuokakt (p. 150) was referred by d'Udekem (1, p. 545, and 

 5, p. 12) to the genus Lumbriculus — 'a cause du developpement des vaisseaux lateraux du aysteme 

 circulatoire.' These were described by the authors who named the species as being very long and 

 much convoluted, especially in the anterior segments. 



Clitellio tenuis was described by Leidy as a Lumbriculus (4, p. 148); Vejdovsky (24, p. 51) 

 places it among the Lumbriculidae but as 'incertae sedis.' Vaillant (6, p. 421) doubtfully includes 

 it in the genus ClitelUo. The position of the genital orifices (? male-pores) upon the tenth segment 

 (ninth in Leidy's enumeration) appears to justify its being put in the family Tubificidae, when 

 taken in connexion with the fact that the setae are uncinate and 3-6 in a bundle. The habitat 

 as Vaillant remarks is also in favour of the correctness of this identification. 



ClitelUo irroratus of Veekill (p. 324 and 622), called also a ClitelUo by Vejdovsky (24, p. 45), 

 queried by Vaillant (6, p. 422), is I imagine not a Clitellio ; as Vaillant points out the presence ■ 

 of capilUform setae in the dorsal-bundles is against this identification ; the fact that these setae 

 are not always present suggests the genus Hemitubifex. 



Clitellio dubius of Czebniavsky (p. 327) might be almost anything; it is only known from a 

 fragment of the hinder end of body. There remains only— 



Clitellio arenarius, Savigny. 



Clitellio arenarius, Savigny, Syst. d. Anndl., 1830, p. 104. 



Lumbricus arenarius, 0. F. Mullee, Zool. Dan. Prodrom. 1776, p. 216. 



Lumbricus littoralis, Bkuguieee, Tabl. Encj'cl. 1791^- 



Peloryctes arenarius, Ledckaet, Arch. f. Nat. 1849, p. 161. 



Tubifex hyaUnus, d'Udekem, Bull. Ac. Roy. Belg. 1855, p. 544. 



1 Fide Vaillant. 



