124 Mr. F. E. Beddard on the 
in the fifteenth segment, its calibre being three or four times 
that of the cesophagus. 
The dorsal blood-vessel is single. The cerebral ganglia 
lie opposite to the furrow separating the first from the second 
segment; they may possibly have been pushed forwards 
with the everted buccal cavity. 
There is only a single pair of spermathece, which in com- 
pensation are very large; they occupy nearly the whole of 
the available space in segment 1x., and indeed they materially 
encroach upon the cavity of segment viil., of course pushing 
the septum which divides the two segments in front of them. 
Each spermatheca (fig. 10) consists of a large thin-walled sac 
(sp) filled with hard coagulated yellowish matter ; this commu- 
nicates with the exterior by a duct which is very thick-walled 
and has a metallic yellow colour; connected with the duct is 
anequally thick-walled, somewhat oval diverticulum (d), which 
becomes constricted just before joining the spermathecal duct ; 
at this point it is furnished with two subsidiary diverticula (d'); 
each of these small diverticula is really double and consists of 
two globular sacs (fig. 11, d’) opening by a common duct. 
These minute sacs, less than a pin’s head in size, are opaque 
yellow and contain sperm. The spermathecal duct after it is 
joined by the wide diverticulum becomes somewhat dilated and 
opens on to the exterior just below the mesentery dividing its 
segment from the eighth. So far as I could make out there 
appeared to be some slight variation in the number of the 
small pouches belonging to the diverticula; but as the speci- 
men is a unique one I am not in a position to give details 
the recording of which would have necessitated the destruction 
of the specimen. The sperm-sacs occupy segments x. and X1. 5 
Iam not quite certain whether they reach the twelfth seg- 
ment. The atria have the lobate form so characteristic of 
the Perichetide, but they are nevertheless rather unusual in 
one point of structure: in all atria of this kindof which I am 
acquainted with from figures or description or from my own dis- 
sections the muscular duct which leads to the exterior comes off 
from about the middle of the glandular mass, and is generally 
comparatively short and curved into a horseshoe-shaped form ; 
in Megascolex cingulatus the atria lie on either side of the 
gut, to which they are closely attached ; more generally one 
finds the atria adherent to the ventral parietes. They are 
long and narrow, and extend from the eighteenth to the 
twenty-fourth segment ; although long and narrow, they have 
not the tubular form found in the atria of Acanthodrilus and 
other genera; they are composed of numerous lobules of 
various sizes. ‘The duct, however, comes off from the ante- 
