18 GUSTAF ELSEN, ON THE AROTTC OLIGOCHJETA. 



3. Archieuchytranis Lampas n. sp. 



Pl. IV. Fig. 6. 



The supra-cesophagial ganglion is about 1 Vi times longer than broad and in ge- 

 neral form resembles that of the following species (fig. 6. b). 



The receptacle consists of a narrow tube furnished at the top with a sacklike en- 

 largement, quite as long as the tube its< lf, but several times broader. This säck or 

 bladderlike enlargement is bent över, and generally full of spermatozoa (fig. 6. c). 



The vesicle of the efferent duct is small and hardly larger than the penis (fig. 6. d). 



The segmental organs are small, the inner duct being broader, but hardly as long 

 as the outer duct or the middle lobe (fig. 29). 



The perigastric bodies are large and oval or rounded, seen from the side even 

 lanceolate. 



The ovaries in the ll th and 12 th segments (fig. 49). 



The testes in the 9 th and 10 th segments (fig. 49). 



The segments are about 46 not well defined. 



Length of body 8 m. m. 



Width. » » Va m. m. 



The spines 2. 4. 4. 3., the inner ones in each fascicle somewhat shorter than the 

 outer ones. 



Habitat. Jenissej at Dudino, lat. 69° 15. 

 The principal character of this species is the form of the receptacle. The bladder- 

 like enlargement is perfectly translucent and its membranes or walls do not show any 

 sign of cells or glands at all. In the other species of this genus the whole of the recep- 

 tacle and even the enlargement for the spermatozoa, when it exists, are always glandular- 



4. Archieuchytrspius Dicksonii n. sp. 

 Pl. IV. Fig. 7. 



The supra-cesophagial ganglion is about l7 3 times longer than broad, and the 

 posterior margin is only slightly emarginated, the whole ganglion resembling that of the 

 preceding species, only being somewhat more elongate (fig. 7. c). 



The receptacle consists of a long and slender tube, enlarged at the top, or fur- 

 nished with a receptacle proper, about half as long as the tube itself. The tube is al- 

 ways bent or slightly twistecl, and the very top of the receptacle is narrower and bent 

 över (fig. 7. f). 



The vesicle of the efferent duct is long and narrow pr about three times longer 

 than wide. The narrow tube is very long and wound like a skein of thread (fig. 7. g). 



The outer duct of the segmental organs is of about twice the length of the middle 

 lobe, and the inner duct nearly as long as that lobe (fig. 30). 



The ovaries in the 11"' and 12 th segments (fig. 53). 



The testes in the 8 ,h , 9 th and 10 ,h segments (fig. 53). 



