434. FRANK E. BEDDARD. 
end of a narrow and muscular tube. The identity in shape of the 
spermathecee in these two species led me at first to identity this 
species with A. Rose; but it differs very distinctly in the fact 
that the nephridia do not alternate in position asin A. Rose, but 
open always in front of the dorsal pair of sete. The two species 
also differ in the shape of the penial sete (cf. figs. 14, 19). 
The seminal sacs were present in segments Ix and xt 
only. I imagine, however, that in more fully mature specimens 
there would be two other pairs in segments x and x11; in both 
cases they had a racemose appearance, and were attached to 
the posterior wall of their segment. 
The two pairs of atria were identical with those of other 
species ; the penial sete are illustrated in fig. 14. 
Acanthodrilus Rose,! n. sp. 
While A. antarcticus might easily be confused, on a 
superficial view, with A. multiporus, the present species is 
by no means unlike A. nove-zealandiz or A. dissimilis. 
Indeed the external character of the spirit-preserved specimens 
hardly permit the species to be distinguished from one or other 
of the above named, but the internal characters enable A. Rosz 
to be recognised as a perfectly distinct and well-marked species ; 
there is no possibility of confounding it with either A. nove- 
zealandiz or A. dissimilis. The largest specimen measured 
about eight inches in length, the colour of the spirit-preserved 
specimen is arich brown, darker upon the clitellar segment, 
and paler ventrally. 
The prostomium completely divides the peristomialsegment. 
The sete are paired; the pairs are, at any rate in the posterior 
region of the body, equidistant; this region of the body is quad- 
rangular in section, the setze occupying the four angles. 
The clitellum occupies segments x1v—x1x (inclusive) as in 
A. nove-zealandie. 
The position of the atrial pores calls for no special remark 
as they are identical in position and appearance with those of 
A. nove-zealandiz. 
With regard to the internal anatomy there are two principal 
1 Named after Dr. D. Rosa of the “ Museo Zoologico,” Turin. 
