THE OLIGOCH^TA TERRICOL^. PART I. 193 



its sete is precisely like those of the 2 species with which it 

 must be compared. A description of one will serve for that of 

 the other. The only recognizable diiference which serves to 

 discriminate the species externally is the condition of the male 

 pores upon segment XVIII. These pores are rather widely 

 separated, much as in P. alhohrunnea. There are, however, only 

 about 8 to 10 setse between them, since the setse cease a little 

 way before the actual male pore. The latter is very conspicuous 

 on each side of the body, although it is rather the elevation upon 

 which it is borne than the actual orifice which is of large size. 

 In the neighborhood of these pores, there are no genital papillse ; 

 and it is the lack of these structures which at once distinguishes 

 the present species from its allies. As all the 6 individuals of 

 the species were the same, this character seems to me to be fully 

 established as distinctive. 



In its internal characters, Pheretima sodalis is somewhat inter- 

 mediate between its near allies P. orientalis and P. albobrunnea; 

 and it possesses, also, some characters peculiar to itself. Thus 

 the septa of certain segments appear to me to be more strength- 

 ened than in either of the two species which I have just described. 

 This was particularly the case with septa VI/VII and VII/VIII. 

 Moreover, in the region of the gonads more segments are thick- 

 ened than in those species of Pheretima, for in Pheretima sodalis 

 the last of these specially thickened septa separated segments 

 XIV/XV. As in the other two species, septum IX/X was present 

 and septum VIII/IX absent. 



The alimentary tract is like that of the two allied species and 

 the cseca are present, but blunt and short. The last hearts are 

 in segment XII. There are 3 pairs of sperm sacs in segments 

 X — XII. In segment XIV is apparently a pair of ovisacs of 

 considerable relative size, and in any case larger than the ovaries 

 of segment XIII. 



The spermiducal glands are large like those of P. orientalis, 

 and there is the same tendency to division into finger-shaped, 

 narrow, parallel lobes. They occupy segments XVI — XX. The 

 duct runs at first forward and then backward, opening about 

 opposite to its original emergence from the gland in segment 

 XVIII. The spermathecse are on the other hand rather more 

 like those of P. alhohrunnea. There are 5 pairs lying in hne. 

 The club-shaped diverticulum is not so long as the main pouch 

 and opens into its narrow duct near the external extremity. 



111310 6 



