PROBOSCIS OF SYLLIDRA 395 
agland. Inthe Exogoneae this gland, which I have termed 
the anterior proventricular, is more conspicuous than 
in the other groups of the Syllidea owing to its being more 
distinctly marked off; but in the latter it is quite as important 
so far as relative development is concerned (fig. 7). The 
cuticle in this region is as thick as it is throughout, and appears 
quite imperforate, so that the secretion of the gland must 
find its way out elsewhere. As in Exogoneae, in fact, 
the ducts of the gland-cells ran back through the epithelium 
to the anterior region of the proventriculus, where the cuticle 
is very thin and, apparently from its staining reactions, not 
strongly chitinized. Here most of the ducts terminate, though 
some appear traceable for some distance in the region behind 
the chitinous plates. 
Kisig describes the structure of the pharynx correctly as 
regards the greater part of its length. The change which 
takes place at the posterior end he describes rightly as regards 
the epithelium, but he falls into an error in stating that in this 
region the structure corresponds closely with that of the ventri- 
culus, not only in the modification of the epithelium, but 
in the development of radial muscular fibres. 
Malaquin gives a more exact account of the structure as 
far as the Syllidae and Husyllidae are concerned. He 
recognizes the glandular modification of the epithelium at the 
posterior end, but assumes that this has to do with the growth 
of the pharynx and the formation of additional chitin. In 
Amblyosyllis and Autolytus, with elongated coiled 
pharynx, he places the glandular region towards the middle 
instead of at the posterior end, i.e. instead of at the opening 
into the proventriculus, where it occurs exactly as in the 
Syllidae and Exogonae. 
In connexion with the pharynx and its papillae mention 
has been made of the pharyngeal glands, the secretion of 
which is discharged on the surface of the latter. As I have 
pointed out (7, p. 229), these glands were referred to by 
Claparéde (2) and De Saint-Joseph (11) and were fully de- 
scribed by Malaquin (9). They consist, in most cases, of about 
Z2 
