42.4. FRANK E. BEDDARD. 
developed gizzard. In comparing this gizzard with that of Pon- 
todrilus I do not find a great difference between them. Ona 
dissection of A. georgianus it is impossible to recognise 
the gizzard at all; it is clear, therefore, that in this species the 
gizzard is either disappearing or in course of development, as 
it isin Pontodrilus. Michaelsen makes no remark upon the 
presence or absence of a gizzard in A. georgianus. The 
seven anterior segments are large, occupied by the masses of 
cells which are usually termed salivary glands ; these extend 
back beyond the pharynx and cover the beginning of the ceso- 
phagus. It is necessary to dissect them away before the 
cesophagus can be seen or the septa, which begin to be obvious 
between segments 5, 6. In the tenth segment the ceso- 
phagus alters its character; the lining epithelium no longer 
consists of tall narrow cells, as in the preceding section; the 
cells become smaller and cuboid in shape, and the whole 
epithelium becomes much more folded; at the same time 
a blood-sinus is developed between the epithelium and the 
muscular walls. I imagine that this part of the cesophagus 
represents an undifferentiated condition of the calciferous 
glands; in any case there was no other trace of the calci- 
ferous glands in the three specimens which were dissected or 
cut into sections. In the fifteenth segment the cesophagus 
again alters its character, the blood-space disappears, and the 
lining epithelium acquires a columnar character ; in the six- 
teenth segment the cesophagus abruptly widens and becomes 
the intestine. 
The intestine has just the merest trace of a typhlosole ; this 
is represented by a very inconspicuous fold. 
Vascular System.—tThe dorsal vessel is single, and j is con- 
nected with the supraneural by five transverse vessels occu- 
pying segments 1x—x111. Of these the last four are the 
largest. 
There is no subneural vessel. I have never met with this 
blood-vessel in any species of Acanthodrilus. Some re- 
marks upon its presence or absence in other Earthworms will 
be found on p. 478. 
