DESCRIPTIONS OF GENERA AND SPECIES 245 



BONNET, who figures a recognizable Tubiftx, and from the sentence 'seta antice utrinque porrecta,' 

 which I take to refer to the capilliform setae of anterior segments, and from his description of the 

 tubes fabricated by the worm (also referred to in another work, 2, p. ico, note 28, and p. 102, note 29). 

 No genus of Tubificidae, except Tubifex, has been stated to fabricate a tube (see, however, Embolo- 

 cephalim). CLAPAREDE'S species T. Boniiefi is, as has been pointed out by NASSE, VE.TDOVSKY, and 

 others, identical with T. linilaniin ; the principal point of difference used by CLAPAREDE in 

 distinguishing the species, viz the position of dilated contractile hearts in viii. instead of vii. is 

 no doubt due to a wrong enumeration of the segments on the part of D'UDEKEM. DIEFFENBACH, 

 though of opinion that the two 'species' are the same, uses the name T. Bonneti, which is hardly 

 permissible. T. rivulonim, described by MACINTOSH, comprises, as he himself has pointed out, two 

 species; one of these 1 believe to be an Ilyodrilus; the larger ('from the lakes' of Scotland) is, 

 judging by the figure of the setae (pi. ix, fig. 3), identical with Tubifex rivulorum. LEIDY'S titrephuris 

 iii/i/iN is doubtfully included by VAILLANT among the synonyms of T. rivulontm. VEJDOVSKY (24, 

 p. 45) regards it as ' incertae sedis' and suggests its probable identity with one of the North 

 American Tubificids described by EISEN (12). The position of the clitellum ('posterior to the 

 ninth articulation'), and the form of the setae (figs. 6, 7) taken together argue that it is a 

 Tubificid of some kind; the shortness of the oesophagus points in the same direction but in 

 Tubifex itself the oesophagus occupies only segments iii. and iv. (D'UDEKEM, VEJDOVSKY, NASSE), 

 whereas in Strephuris it is said by LEIDY to reach the sixth segment. I therefore repeat VAILLANT'S 

 query in my list of synonyms. VAILLANT includes among the synonyms Ilyodrilus coccineits, in spite 

 of STOLC'S papers upon the structure of this worm, one of which is included by VAILLANT in his 

 list of literature, and indeed partly abstracted (VAILLANT, p. 349). I do not include /. coccineus 

 among the synonyms of T. rini/nnim. With regard to Saenwig taurica, S. peculiaris, and S. diver- 

 Kiaffosa (with two rars.), I am quite of the opinion of VAILLANT that they do not differ from 

 Tubifex- rmilonim as they are described by CZERNIAVSKY. At the same time I may point out that 

 there is nothing in the latter naturalist's definitions ' which militate against their transference to 

 the genus Hemitubifex or Ilyodrilus; T. diaphanus of TAUBER, and T. longicauda of EESSLER are 

 also possibly synonymous; as regards the former it is stated that the uncinate setae are ' nonpalniate ' ; 

 this probably refers to the pectinate setae of Pxammoryctes umbelifer. If the slight additional processes 

 found in T. riculonint were absent from this species it is probably an Ilyodrilus or Hemitubiftx. 



(2) Tubifex blanchardi, VEJDOVSKY. 

 T. blanchardi, VEJDOVSKY, Me"m. Soc. Zool. Fr. 1891, p. 596. 



Definition. Length alout 25 mm.; number of segments, 62. Setae of all bundle* uncinale only. 



Hab. Algeria. 



The setae of this worm, though they are everywhere uncinate, differ slightly in 

 different regions of the body. The dorsal setae of the anteclitellian segment are 

 equidentate, Lut there is occasionally a median denticle. The dorsal setae of the 

 postclitellian segments have the superior denticle longer than the inferior; the same 

 is also the case with the ventral setae of the same segments, but the ventral setae 

 of the anterior segments are exactly the reverse. Sexual setae accompany the 



1 They principally relate to minute differences in the form of the uuciiiute rt:u. 



