892 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [14] 



Integumeut furnished with only two kinds of spines, viz, hair-spines 

 and forked spines. Fan-shaped or pseudo comb-like spines never pres- 

 ent. N 



As can be seen, the above characteristics are neither very pointed 

 nor at all sufficient to fully characterize the genus, but the descriptions 

 of the different species belonging to this genus are mostly so inade- 

 quate that no better genus-characteristics could at present be compiled. 

 Of the four species known.I have seen only one, viz. Tub. campanulatus. 

 Tub. Bonneti is sufficiently described by Claparide, and seems easily 

 distinguished fromany other. Of the remaining two species, I have 

 seen neither specimens nor descriptions, and must, in regard to them, 

 trust to the authority of the respective authors. 



TuBiFEX RivuLORUM TJdekem, 1853. 



Syn. : Tubifex rivulorum. 



D'Udekem, J. Hist. Nat. d. Tub. riv. Mem. Conr. par. I'Acad. d. Belgigne, 

 Tom. XXVI, 185.5. 



Tubifex coccmEUS Yejdovsky, 1875. 



Syn. : Tubifex coccineus Yejdovsky. 



Sitzungsb. Mathend, Nat. vissenscb. Classe d. Bobm, Gesellseh Wessenschaft, 

 Oct. 29, 187.5, p. .3. 



This and the following species. Tub. Bonneti, are said to have the 

 receptacle in the tenth, and the sexual pore in the eleventh segment. 



Tub. rivulorum and Tub. campanulatus, on the contrary, have the same 

 organ in the respective segments, 9 and 10, or in one segment nearer 

 to the cephalic lobe. I can hardly account for this seeming difference 

 in any other way than that the respective investigators have counted 

 the segments in different ways. It is natural that when every investi- 

 gator has not only had his own way of counting the segments, but also 

 changed that way at different times, tiiat much confusion will ensue. 

 For our purj)ose it is materially indifterent if we count the cephalic 

 lobe as a segment per se, or if we, as the first segment of the body, 

 assign the first setigerous one, if we only can agree to one or the other. 

 Myself and d'Cdekem count the first setigerous segment as the first 

 segment of the body, and accordingly we find the receptacle to be sit- 

 uated in the ninth and the sexual porus in the tenth segment. Clapa- 

 rede and Vejdovsky, on the contrary, consider the first setigerous seg- 

 ment to be the second segment of the body, which, of course, places the 

 sexual porus in the eleventh segment. 



I have, to prevent further complications, and in order to immensely 

 simplify the counting of the segments, here adopted the plan to name 

 the segments surrounding the oral orifice, respectively the cephalic lobe 

 and the buccalic segment; and, further, to assign the name of the first 

 segment only to the first setigerous one. And, to avoid any possible 

 misunderstanding, it would, when speaking of the segments, be well to 

 add "setigerous." 



