KONGL. SV. VET. AKADEMIENS * HANDLIN GAlt. BAND. 15. N:0 7. 21 



The testes in tlie 9 tk and 10 th segments. 



The perigastric cells are not free, but form a thick stratum especially in the front 

 part of the body. 



The segments are very well delined and abont 56. 



The length of the body of the largest spechuens about 25 in. m. 



The widtli of dito 2 m. m. 



The spines abont 6. 7. 7. 6. 



5. 6. 6. 5. The inner ones are shorter than the outer ones. 



Habitat. The range of this species is rather wide, as it is fonnd all along the 

 Jenissej: Jefremon Kamen 72° 40'; Mesenkin 71° 20'; Dndino 69° 15'; Troitskoj 65° 45'; 

 Nischnij Imbatsk 65° 50'; Worogowa Selö 60° 50'. 



On Novaja Semlia, where so ma ny allied species are found, it does not seem to 

 exist at all. 



As this species seems to be closély allied to the following species, A. affinis, and 

 as intermediate forms between them may perhaps be fonnd, I sliall first describe that 

 species, before I venture to enter upon a comparison of their respective characteristics. 



8. Archienchytraeus aftinis n. sp. 



Pl. VI. Fig. 11. 



The supra-cesophagial ganglion is longer than broad, and its posterior emargina- 

 tion is somewhat more shallow than that of the preceding species (hg. 11. c). 



The receptaele is of a variable form, its enlargement is sometimes cylindrical, 

 sometimes conical (fig. 11. d). 



The vesiele of the efferent duet is generalty long and twisted like a corkscrew, 

 and not furnished with any peculiar ring round the interiör opening (fig. 11 f). 



The segmental organs are exactly similar to those of the preceding species. 



The ovaries are situated in the ll th and 12 th segments. 



The testes in the 8 th , 9 Ul and 10 th segments. 



No perigastric cells found. 



The spines in each fasciele 4. 4. 5. 4. the inner ones being scarcely, or not at all, 

 shorter than the outer ones (fig. 11. a). 



The length of the body about 15 m. m. 



The width of the same about 1 in. m. 



The segments well defined and abont 54. 



Habitat. Dickson harbour at the mouth of the river Jenissej and at Schaitan- 

 skoj, 71° 55'. 



As I have mentioned above, this and the preceding species are closely allied and 

 resemble each other in many of the principal points, especially in regard to the re- 

 ceptacles and the segmental organs, therefore I hesitate to describe them as different 

 species. Still, as may be seen from the characters given, there are several points in 



