to 
CALIFORNIA EUDRILIDA®, 
below are Microscolex dubius of Rosa and HLudrilus dubius of Fletcher, I will first 
refer to the latter. Fletcher’s description is sufficiently minute to allow us with cer- 
tainty to refer it to the genus, but the details are wanting to such an extent, that it is 
difficult to understand its further relationship. There are three points in the deserip- 
tion which are of special interest. 
1. Absence of spermathece. 
2. The beginning of the nephridia in v. 
3. The junction of the spermduct and the prostate half-way between the 
glandular part and the body-wall. 
As to the first of these the spermatheee may be really wanting or it may have 
a substitute similar to the one found in Deltania elegans as described below. At any 
rate this character brings the species Hudrilus dubius close to Deltania elegans as well 
as to Beddard’s Wicroscolex Poultoni. 
The beginning of the nephridia in somite y brings 2. dubius close to Beddard’s 
species but separates it distinctly from De/tania elegans in which the nephridia com- 
mence in i, as will be shown below. 
The third character requires to be reaffirmed and described more in detail. 
The joining of the spermduct and the prostate is always of the utmost importance and 
interest and a mere general statement will not suffice for properly characterizing a 
species, especially when the group is little known. 
Rosa at first considered #. dubius to be identical with his JJicroscolex mod- 
estus, but a later investigation of new material convinced him of the distinct char- 
acter of the species and he then describes both as two different species of Microscolex. 
It must therefore be considered certain that the deltoid arrangement of the ventral 
setee does not occur in JMicroscolex modestus. In regard to the respective species of 
E. dubius and M. dubius described by Rosa and Fletcher, I am not fully persuaded 
that both actually belong to the same species, and I believe that nothing short of an 
actual comparison of the specimens can decide if they do so. 
Beddard has at two different times described species of the genus Microscolex, 
but which differ from each other in several important points. Wicroscolex novwe-zelan- 
die resembles the old genus Rhododrilus in the independent opening of the spermduct. 
Instead of referring the above species to Microscolex, and merge Rhododrilus in the 
latter genus, I consider it more proper and convenient to retain Rhododrilus and re- 
fer JL. nove-zelandic to it, as the independent opening of the spermduet appears to 
me of sufficient importance to be considered a generic character. Another species, 
Microscolex algeriensis, also described by Beddard, ean, I believe, best be retained in 
the genus Microscolex, as it evidently possesses the sete parallel throughout the 
ventral side of the clitellum. 
Microscolex Poultoni however is probably a true Deltania and Beddard’s excellent 
description leaves no important characters in doubt. 
In his description of Microscolex Poultoni, Beddard refers especially to the 
deltoid arrangement of the sete in the clitellial somites. He says: “ From segment 
