OLIGOCHATA OF TROPICAL EASTERN AFRICA. 217 
bound the sperm mass of the 11th segment anteriorly is to 
be regarded as a development of these muscular threads. In 
another specimen, however, this peculiar disposition of the 
septa was absent. 
The spermatothecal panel of this species is single and 
median, extending from its opening on the border line of the 
12th and 13th segments for three or four segments posteriorly. 
Anteriorly, also, it extends for a short distance beyond the 
external pore. This portion of the sac is conical in form, as 
is shown in the figure (fig. 22). The general appearance 
of the spermatotheca is closely similar to that figured by 
Michaelsen for Notykus emini (loc. cit. on p. 1, Taf. ii, 
fig. 8). The spermatothecal sac is also, as in that worm, 
without lateral branches, such as occur in Stuhlmannia 
and form a ring round the gut. There is, moreover, a further 
point of resemblance to Notykus illustrated in my figure, 
which may be compared with that of Michaelsen. Round the 
base of the sacin Notykus are represented in Michaelsen’s 
drawing a pair of small glands lettered “nt.” It is described 
by Michaelsen as “ein kleines muskuloses Polster .... 
wahrscheinlich mit einem Hohlraum versehen, welcher durch 
die oben erwahnten spaltformigen Offnungen neben der Samen- 
taschen-Offnung ausmiindet.”’ I shall revert to the probable 
nature of these organs later. The anterior part of the spermato- 
thecal pouch which lies in the 12th segment is histologically 
different from the region which it precedes. There is in this 
particular a remarkable analogy between these sacs which 
function as spermatothecz and the true spermatothece of, for 
example, the Perichztide. In the latter the diverticula of the 
spermatothece have invariably a different structure from the 
pouches of which they are diverticula. This, it will be noticed, 
is also the case with the spermatothecal sac of the present 
worm. When the sac is examined by a series of transverse 
sections, from in front backwards, the first pair to appear in 
the series is of course the anterior diverticulum already 
referred to. This (fig. 23) is seen to have a circular form in 
section, and it presents a most curious resemblance to a 
