264 OLIGOCHAETA 



There is at present but one species known, viz. T. vejdovskii; but as the external 

 characters are similar to those of Limnodrilus and Clitellio, it is possible that some 

 of the species doubtfully referred to these genera may belong to Telmatodrilus. 



Telmatodrilus vejdovskii. EISEN. 

 T. vejdovskii, EISEN, Bih. K. Svensk. Akad., 1879, No. 16, p. 8. 



Definition. Length 35-50 mm. Intestine begins in XI; pigmented peritoneal coating of intestine 

 begins in XV. Nephridia with vesicular peritoneal cells and without dilated end sac. Hob. 

 California, at an altitude of 6,000-1 0,000 ft. 



The worm is described by EISEN as being torpid in its habits, not active like 

 many Tubificidae ; it lies in the mud as does Tubifex, &c. with the tail protruding. 

 The setae are eight to fifteen in number in each bundle ; in the adult they are 

 sigmoid without terminal bifurcation, which is only apparent in young specimens. 

 No spermatophores were found in the spermathecao. 



Genus ILYODRILUS, EISEN. 



DEFINITION. Capilliform setae in dorsal bundles, uncinate setae with a web, 

 penial setae, not very different from ordinary uncinate setae, in neighbourhood 

 of male-pores. An integumental plexus of blood-vessels present. Nephridia 

 with a dilated region after funnel. Spermiducal gland with thick covering of 

 gland-cells ; no spermatophores ; ova develop as in Naids. 



It seems to me to be not a little doubtful whether this generic name can be 

 retained. The name was applied by EISEN (12) to a number of species of Tubificids 

 found in California, which I cannot differentiate from the genera Tubifex, and 

 HemituMfex. To this genus (Ilyodrilus) STOLC (3) referred the species described by 

 VEJDOVSKY (11) as Tubifex coccineus, and later (24) as T. rivulorum, var. coccineus. 

 STOLC has given an elaborate account of the structure of ' Ilyodrilus ' coccineus, 

 which appears to me to prevent anyone from placing it in the same genus as any 

 of the three species described by EISEN as Ilyodrilus. EISEN'S Ilyodrilus has small 

 separate prostates, which are absent from /. coccineus; it has not penial setae which 

 are present in /. coccineus, as was first pointed out by VEJDOVSKY (p. j 56, footnote) ; 

 the only resemblance of importance seems to be that in /. sodalis the eggs develop 

 in the same way as in I. coccineus, and that in the American worms no spermato- 



