40 Memoirs of the Indian Museum. [Vor. VI, 
In addition to the above remarks there are a few points of more or less general 
interest to students of the Oligochaeta, which have recently, —in part during the 
preparation of the present paper, — suggested themselves to me for brief discussion ; 
though I cannot pretend that the species described in the main part of the paper offer 
more than a convenient peg on which to hang my remarks. 
THE PHARYNX IN THE ENCHYTRAEIDAE. 
The usual condition in which what is sometimes called the ‘ pharynx’ of Enchy- 
traeids presents itself in sections is that of a flat raised plate of high columnar 
epithelium, with very definite edges, on the dorsal wall of the alimentary tube 
immediately behind the buccal cavity; this is shown, for example, for Enchytraeus 
barkudensis in fig. I of the original description of the worm (23). This plate is 
sometimes described as ‘ suckerlike’ —at least it has been so by myself,—with, cer- 
tainly, a suspicion that it might be everted from the mouth aperture and applied to 
the substratum for the purpose of adhesion after the manner of an actual sucker. 
Fig. ı shows that such eversion may take place; a number of specimens of E. bar- 
kudensis (belonging to a previous capture from the Chilka Lake) appear to have 
everted the pharynx at the moment of fixation. A similar phenomenon is recorded by 
Baylis (1) for a species which he describes as Enchytraeus carcinophilus. 
But whether the plate when everted can act as a sucker, for adhesion, possibly 
for help in progression, seems to me more doubtful. The muscular fibres (m. ph., fig. I) 
attached to the epithelial plate might be supposed by contraction to withdraw the 
centre of the plate, and so, as for example in a sucker of Sepia, to produce a vacuum 
between the centre of the plate and the substratum; but the firm margin, capable of 
maintaining a close apposition, is wanting, and the high columnar un seems 
an unsuitable sort of covering for such an organ. 
The use of the everted pharynx as a means of adhesion and progression in Aulo- 
phorus tonkinensis (belonging to the Naididae) is well established (Annandale apud 
Michaelsen, 9; Stephenson, 18); but under ‘pharynx’ is here included the whole 
circumference of the alimentary tube (‘‘ the pharynx is large and wide’’),—hence the 
meaning of the word is different from that in which it is used above in connection 
with the Enchytraeidae. x 
It is possible that the plate might be the central plug of the sucker, the margin 
being formed by the surrounding structures, —prostomium and everted portion of 
buccal cavity, cf. fig. 1). But I would suggest rather that the plate is sensory in func- 
tion, and may be extruded for the purpose of exploration, or possibly also for picking 
up minute food particlesby adhesion. 
Another condition of the pharynx is shown in fig. 3; the pharynx is here retracted 
so as to appear as a thickwalled hollow hemisphere opening forwards into the 
buccal cavity. The figure is actually drawn from a specimen of Fridericia car- 
michaeli;, but the same condition, only in a more exaggerated form (narrower cavity, 
the upper and lower walls being almost in apposition; narrower mouth projecting 
forwards into buccal cavity) was found in specimens of Enchytraeus barkudensis also. 
