12 
earlier and later investigations on the byssus-gland by A. MüLLEr 
(23), TULLBERG (32), CARRIERE (2) etc. others offer no direct compa- 
rative argument for this interpretation. Perhaps it might quite as well 
be compared to the anal gland described by LaAcazE DUTHIERS (19) 
or later observations might prove it to play some accessory func- 
tion subordinate to the secretion of generative materials. 
At all events the strong muscular investment which is specially 
adapted to surround and enclose it render it probable that its 
contents are at certain moments foreibly expelled in considerable 
quantities. 
Curiously enough the same organ, although in a much less 
developed condition, was found by me in all the three specimens 
(Prof. v. Grarr’s and Ray LANKESTER’S) of Neomenia I had occasion 
to examine. 
In only one of Prof. v. GRAFF’S sections it is shewn and this 
being one of the sections quite close to the anal opening I feel 
convinced, after comparison with the foregoing and with the follow- 
ing sections, that it was this one which induced Prof. v. GRAFF to 
believe that a bridge of spiculiferous integument separates the ven- 
tral groove from the anus (6, p. 559). I give an outline of 
this section in fig. 35. The apparent coecum ic communicating 
as in Proneomenia with the anal cavity, is filled with what looks 
like large spicules perpendieularly placed, although calcareous 
matter does not seem to be contained in them. The cellular layer 
is present too, but the surrounding muscles do not attain to 
such a marked development as in Proneomenia. I find the same 
shallow,, coecum-shaped arrangement, with similar contents in Prof. 
LANKESTER’S specimens. 
So both the histology and the situation appear to point towards 
the existencee of a direct homology with the organs that were 
above described for Proneomenia. But no new light is thrown 
upon the question of their significance in the animal economy by 
this fact, ; 
