242 
FRANK E. BEDDARD. 
analogous to that of a salivary gland ; it may be at least 
admitted that its function is probably different from that of 
the nephridia in the remaining segments of the body. A 
comparison between the structure of the mucous gland in the 
two genera Dichogaster and Urochseta leads to the 
inference, firstly, that they are homologous, and secondly, 
that they present two stages in the evolution of the gland. 
The primitive characters are more completely retained in the 
mucous gland of Urochseta; it possesses funnels and opens 
on to the exterior of the body on the first segment; the reduc- 
tion in the number of the funnels, correlated with the changed 
uses (?) of the gland, culminates in Dichogaster, where there 
are no ciliated funnels ; at the same time the external aperture 
comes to be situated in the buccal cavity. 
I have elsewhere (7) described a similar gland in Acantho- 
drilus novse-zealandise which, like that of Dichogaster, 
opens into the buccal cavity. I could find no ciliated funnels. 
In this case, as in that of Dichogaster, I discovered (see p. 
259) the ciliated funnels of the nephridia elsewhere, and their 
absence from the mucous gland rests upon observations which 
are therefore more to be trusted. 
Benham (9, No. 2) has recorded a gland in Diachseta which 
occupies the same position and has the same general appear- 
ance as the mucous glands of the types already referred to. 
He states that it is not a branched gland, but consists only of 
a single much contorted tube. 
In Acantliodrilus annectens (Beddard 8) there are 
a pair of anterior nephridia exactly like those of A. multi- 
porus; and each opens in the same way into the buccal 
cavity. I cannot discover very much evidence of this gland 
being branched ; but fig. 14 appears to show that branching of 
the tubules does occur, though apparently not to any great 
extent, 
There is nothing in the facts so far which is contrary to 
Eisig’s supposition that the branching of the nephridium, 
whether of the terminal (external apertures) or distal (coelomic 
funnels) region, is secondary; on the other hand, these facts 
