CONTRIBUTIONS TO THE ANATOMY OF KARTHWORMS. 425 
In the cesophageal region immediately underlying the vas- 
cular tract of the cesophagus, and extending through two or 
three segments, is a longitudinal trunk, about the presence of 
which in other Earthworms there is some dispute. I have 
recognised it in A. georgianus, both in transverse and lon- 
gitudinal sections. There can be no doubt as to its presence, 
the calibre of the vessel being quite as large as that of the 
supraneural trunk. 
I have described this vessel in A. dissimilis and other New 
Zealand species (1). 
It also occurs in Eudrilus sylvicola (see Beddard, 2) 
and among aquatic Oligocheta, in Bothrioneuron and Lo- 
phocheta (see Stolé, Tab. ii, figs. 5, 6, sb). 
Professor Howes has figured a corresponding vessel in 
Lumbricus in his ‘ Atlas of Biology.’ It is described in the 
‘Practical Biology’ (p. 260) as the “‘subintestinal vessel ; ” 
but some doubt is thrown upon the existence of this vessel 
by Benham (10, p. 253) and by Jackson (27, p. 203, foot- 
note). 
I have failed to find any penetration of the capillaries within 
the epidermis either in this or in any other species of Acan- 
thodrilus, except of course in the clitellum. 
Generative Organs.—The testes and ovaries have been 
described by Michaelsen; they occupy the usual position— 
the testes in X and XI, the ovaries in XIII; these organs 
are attached, as is usually the case, to the anterior septum of 
their segment. The most striking variation from this normal 
position occurs in this genus ; in A. annectens I have already 
(3) recorded the fact that the gonads are attached in the im- 
mediate neighbourhood of the funnels of the generative ducts to 
the posterior wall of the segment. I have taken the opportunity 
of re-examining the position of the gonadsin A. multiporus, 
a species which comes near to A. annectens; I find that while 
the testes have the normal position, i.e. are attached to the 
front wall of their segment, the ovaries are, as in A. an- 
nectens, attached to the hinder wall of the thirteenth 
segment, 
