EARTHWORMS 415 



Michaelsen has suggested that the species which I described in my prehminary 

 paper as Perichaeta molokaieusis, is really identical with Fletcher's Perichaeta peregrina, 

 or is at least to be regarded as a " fragliches synonym." At the time that I described 

 that species I was not so convinced as I am now of the unimportance of size as a 

 distinguishing characteristic of species of this genus. Fletcher described his species as 

 being 19 cm. in length, i.e. nearly double the length of the individuals of ''Perichaeta 

 molokaieusis" examined by myself Moreover Fletcher has not given any details about 

 the clitellar setae, beyond stating that they are present. This again is a matter which 

 is apparently not of such importance as I thought ; that is to say, the same species may 

 have setae upon one, two or three or perhaps even none of the clitellar segments. 



There can I think be no doubt as to the identity of Benham's ''Perichaeta 

 flowej'i" with the present species. Benham states that there are 12 setae between the 

 male pores, which is the number given by Fletcher. I counted 15 in my specimens. 

 But the difference is clearly negligible. Benham particularly mentions the clitellar 

 setae as being present on segment 16 only, a state of affairs which I found also. None 

 of the three forms comprised in the present species possess copulatory papillae ; hence 

 it is now probably to be taken as a character of this species. In this as in all other 

 points 1 can detect no differences between the descriptions of Benham and of myself. 

 We are clearly dealing with the same species, which being with very great probability — 

 almost amounting to certainty — identical with that described as " Perichaeta peregrina" 

 by Fletcher, must bear that name. I now give for the sake of others who may doubt 

 this identification a description of my specimens. 



The two individuals of this species which I have examined were 103 and 81 mm. 

 respectively in length. The former specimen possessed 88 segments, the latter 93. 



The prostomium is small and continued by grooves on to the first half of the first 

 segment. 



The dorsal pores commence upon segments 10, 11, and are visible upon the 

 clitellum. 



The clitellum occupies the usual segments, 14 — 16, and has few setae upon its last 

 segment. 



The male pores are not jarominent and are separated by i 5 setae. 



I observed no genital papillae. 



The first septum separates segments 4, 5 ; none are thickened specially. 



The gizzard occupies the usual segments which are not divided by septa. 



The intestine begins in 1 5 ; the caeca are present and not large. 



The sperm sacs are large and occupy segments 11, 12. 



The spermiducal glands extend from segments 17 — 21 or 22; they are broken 

 up into lobes which have to some extent a relation to the segmentation of the gland. 

 The curved duct communicates directly with the exterior and not through the inter- 

 mediary of a terminal dilated sac. 



F. H. II. 54 



