$2 A. CO. OUDEMANS. 
proboscidian channel” of McIntosh (26) (better “infra-pro- 
boscidian-sheath-channel”). It is separated from the two 
others and from the sheath by a horizontal broad band of 
transverse fibres (cf. Carinoma). 
The next section shows us six lacune, for each of the three 
lacunz is divided into two by transverse fibres, viz. the lacunz 
on the sides of the proboscidian sheath are divided into an 
upper and a lower one, whilst that beneath the sheath into one 
right and left. 
A little further backwards the transverse bands in the 
lacunz on the sides of the proboscidian sheath disappear, and 
so we have again four lacunz, one on each side of the sheath, 
and two beneath it, just as in Carinoma. 
At the same time we see on each side a great ganglionic 
mass penetrating the circular layer. These are the posterior 
lobes (brain respirators). As soon as they are within the 
circular layer they are surrounded by a thin lacunar space, 
thus they are bathed (McIntosh) by a lacuna. These lacune 
as soon as the posterior lobes disappear, immediately unite 
with the two lacunz beneath the proboscidian sheath, which in 
the meanwhile have moved from one another. 
Besides the two brain respirators, still two smaller club- 
shaped ganglionic masses penetrate into the two lacune on the 
sides of the proboscidian sheath (are they brain processes ”). 
The two lacune on the sides of the sheath are wholly sepa- 
rated from the other lacune, even from those in which the 
two posterior lobes bathe, by the above mentioned horizontal 
band of transverse muscular fibres. After the disappearance 
of the lobes this band also disappears and the four lacune now 
coalesce into two. 
This coalescence, however, is of very short duration, for they 
are again divided by transverse bands. The mouth becomes 
visible. The circular muscular layer in its lower portion is 
interrupted, deviates outwards, and finally encloses the ceso- 
phagus. The lacune and the longitudinal muscular layer, 
which always remain against the inner side of the circular 
layer, do the same as the circular layer (fig. 50), so that as 
