510 FRANK BE, BEDDARD, 
band has disappeared (cf. Kowalevsky, 18, pl. vii, fig. 26), the fact 
is not remarkable. In Allolobophora, however (Vejdovsky, 1, 
pl. xvii, fig. 9; pl. xviii, fig. 9), the ciliation of the ventral 
surface persists later. 
In fig. 18 of Pl. XXXI is represented a longitudinal section 
through the first few segments of the youngest embryo. Just 
above the stomodzeum and in front of the cerebral ganglia is a 
group (S) of three or four cells bearing long cilia: as I have not 
been able to compare these cilia with those which probably, as 
in other genera, form a band along the ventral surface of the 
embryo, it is impossible to say if they differ in any way ; but 
by comparing them with the figures given by the various 
authors who have studied the development of Lumbricus, 
Allurus, and other Oligocheta, I should imagine that they 
will prove to be much longer and stronger cilia. Furthermore, 
the epiblastic cells which bear them are specialised ; they differ 
from the neighbouring cells in their greater size. 
In several Oligocheta the ventral ciliated band extends 
on to the dorsal surface of the stomodeum—in Lumbricus 
trapezoides, forexample. Vejdovsky also figures (1, Tab. xvi, 
fig. 4.) cilia upon the dorsal lip of the stomodzeal invagination 
in Allurus tetraeder, and in an earlier embryo (Tab. xvi, 
figs. 5,11) of Allolobophora feetida. This embryonic con- 
dition is preserved in the adult AJolosoma and in Cteno- 
drilus (if we are to regard that worm as an Oligochete, 
which cannot be safely done until its genitalia are known): in 
both these genera the ciliation is limited to the ventral surface 
as in the embryo Lumbricid, which is an interesting point of 
similarity. But in none of these cases is there any specialisa- 
tion of the cells upon the prostomium which bear the cilia; if 
such a group of cells existed in Lumbricus as I figure in 
Acanthodrilus multiporus, it could hardly, I think, have 
been overlooked; so many competent observers have studied 
Lumbricus with all the improvements of modern methods, 
that so obvious a structural fact could not well have failed to 
be noticed by one or other of them. I can discover nothing 
in the plates of Kowalevsky, Kleinenberg, Vejdovsky, or 
