1892.] SPECIES OF EARTHWORMS. 687 



occupy the same segments, but each has a small irregularly shaped 

 diverticulum sessile upon the duct of the spennatotheca. Finally, 

 the atria are much larger than they are described in Perionyx 

 excavatus or than they are in the species which I here identify with 

 Perrier's Perionyx excavatus ; they are much broken up into lobes 

 and extend through three segments ; the duct, too, is longer and 

 is contorted ; these glands in fact resemble very closely those of a 

 typical Perichceta. 



Some years ago I briefly described a species of Perionyx from 

 Akyab ^ to which I gave the name of Perionyx macintosliii ; this 

 species is admitted by Vaillant ^, but not very heartily allowed by 

 Rosa '. 



I have got two individuals of a large Perionyx which I believe 

 are referable to the same species ; if so it is certainly a " good 

 species." 



My observations upon Perionyx macintoshii were made upon a 

 single, not sexually mature, example ; they were therefore not quite 

 conclusive as to the distinctness of the species, though the large size 

 alone is, as it proves, a suiKcient index of the species, when com- 

 pared with the three others described here. 



The internal anatomy is more hke that of the first species from 

 Seebpore, which 1 propose to term Perionyx intermedius ; the last 

 pair of commissural vessels are in the xiiitli segment; the atria, 

 however, are limited to a single segment, and the spermatothecse 

 have no appendix. The principal differences concern the external 

 characters ; this species has a more extensive clitellum, it reaches 

 from the xiiitb to the xixth segment, being thus longer by two 

 segments than in the other species ; the male pores have not, as I 

 pointed out in my earlier description of the species, the characteristic 

 appearance of those of Perionyx excavatus ; they are placed in a 

 ventral area, but the two pores are not upon separate papillae. The 

 four species of Perionyx referred to in this paper show certain very 

 characteristic differences in the condition of the male pores and of 

 the setae in their immediate neighbourhood, of which the following 

 is an account. 



In Perionyx gruenewaldi the area upon which the atrial pores are 

 borne is not, owing to the small size of the worm, very well marked 

 when looked at through a lens. When this part of the body is 

 submitted to a microscopic examination, the area is seen to be 

 bounded by an obvious groove. The ordinary setae of this segment 

 (the xviiith) do not extend on to this area except on one side of the 

 body, where a single seta is inserted on to the outer edge of the area ; 

 as, however, a groove cuts off the tract of integument which bears 

 this seta from the genital area, it might be held that the line between 

 the genital area and the surrounding integument was indicated by 

 this groove. There are four genital setse on each side which, although 



^ " Note on some Earthworms from India," Ann. & Mag. Nat. Hist. ser. 6. 

 xii. p. 217 (1883). 



^ Anneles in ' Suites a Buffon,' p. 86. 



? " Pericbetidi di Birmania," Ana. Mu3. Oiv. Geneva, ser. 2 a, vol. vi. p, 157 . 



46* 



