17 
size and provided with larger nuclei, which on this account lie 
much closer together. I must leave it for more complete investigations 
to decide whether it will indeed have to be regarded merely as 
the ultimate portion of the posterior foot-gland, or as something of 
an intrinsically different function. I shall designate it by the neu- 
tral name of the pre-anal gland. 
An anterior and posterior foot-gland similarly situaied and simi- 
larly shaped as the above described are equally present in Neome- 
nia. Here too there is a distinet longitudinal slitlike opening to 
the exterior, separated from the mouth by interyening integument 
and posteriorly continuous with the ventral groove. The cellular 
groundsubstance of the anterior foot-gland and the numerous cili- 
ated cavities penetrating into the midst of it, have quite the same 
appearance as in Proneomenia. TULLBERG noticed the duct (31 
fig. 6,1) but both he and v. GrRAFF do not give any further details 
than that it dilates, divides and terminates blindly. The posterior 
gland can likewise be distinetly made out in both Proff. v. GRAFF’s 
and RAY LANKESTER’S sections; in the latter haematoxiline has 
strongly stained the contents, thereby perhaps offering another con- 
firmation for the suggestion of its having a glandular function. 
The further course of the ventral furrow!) offers only few points 
of interest. The way in which the spinous integument joins the 
ciliated columnar epithelium by which the furrow is coated, 
is illustrated in fig. 24 and needs no further explanation. Behind 
the slit for the anterior foot-gland numerous longitudinal eiliated 
ridges of which the five larger ones are of equal height, stand 
out on the bottom of the ventral groove; the middle one of these 
l) Balfour and Sedgwick (1, vol. II, p. 269) have very lately suggested 
that the ventral groove of Proneomenia is probably the homologue of the groove 
which is found in the larva of Chiton and not simply the foot. Embryology 
alone can decide about the value of this suggestion : the present researches do not 
fürnish any sound argument either pro orcontra. Kor&n and Danielssen’s 
observations on living specimens of Neomenia (16) have however clearly shown 
that the funetion of the ventral groove and delicate foot and the way in 
which it is expanded and made use of are closely analogous to what is known 
as to the foot in other Mollusks. 
HusrecHt, Proneomenia sluiteri. b 
