126 MISS G. SWEET ON THE SPERMIDUCAL 
are attached to the posterior wall of the segment, and those im 
segments behind 10 to the anterior wall of the segment. These 
sperm-sacs vary in form as well as in position. Sometimes they 
form definitely shaped masses enclosed in a firm membrane. In 
this case, they are simply lobed or mammillated, or form a ring 
around the alimentary canal. At other times they are much 
looser, racemose structures, when the investing membrane is 
easily broken. Again, the whole cavity of the segment may 
be completely filled by a mass of seminal cells, obliterating 
the cavity of the succeeding segments by backward pushing of the 
septum. In several instances Beddard has cast doubt on the 
character of the sacs in segments 13 and 14 when so existing, 
preferring to regard them as egg-sacs rather than sperm-sacs as: 
described. In no species which I have examined has there been 
any sign of ovain such a position, these sacs invariably containing 
developing sperm. 
II. Spermiducal Glands. 
These are usually found in segment 18 and sometimes in 
contiguous segments, only very rarely extending in front of 
segment 18. The two main types of external form are tubular 
and lobate (including flat and undivided forms). 
(1) Tubular Glands.—These lie either transversely to the 
body, when they are generally confined to segment 18; but in 
some species they may, when mature, extend as far back as. 
segment 26. They are usually slightly coiled, but in some cases, 
e. g., Megascolides roseus and M. australis, they are twisted ixto: 
an almost inextricable mass, lying in segment 18. They are 
characteristic of the following genera:—Megascolides, Orypto- 
drilus (partly), Fletcherodrilus, Diporocheta, and Acanthodrilus.. 
With regard to Digaster, it will be noted that the two species. 
D. excavata and D. queenslandica are somewhat different from 
the remainder of the genus, more especially the former species. 
They have been described as bilobed, with a flattened lobe: 
anteriorly and a long tubular portion posteriorly. In the 
specimens of D. excavata examined by me only tubular “ pro- 
states” have been seen, though in one individual a band of 
connective-tissue in the position described for the gland-duct 
might possibly be mistaken for a duct. It, however, does not 
contain any duct whatever, the true gland-duct leaving the 
