STRUCTURE OF GLANDULAR VENTRICLE OF SYLLIS. 471 
On the Structure of the so-called Glandular 
Ventricle (Drusenmagen) of Syllis. 
By 
William A, Haswell, M.A., B.8c., 
Lecturer on Zoology and Comparative Auatomy and Demonstrator of 
Histology, Sydney University. 
With Plate XXV. 
IntRopuctory AND HisrTorRiIcat. 
In all the Syllidz the regions of the alimentary canal (fig. 
1) have a very characteristic structure and arrangement. The 
mouth opens into a buccal chamber, through which the pro- 
trusible proboscis is capable of being everted. The anterior 
portion of the latter— proboscis proper, ‘‘ région pharyn- 
gienne” of Quatrefages '—is thin-walled, presents a circlet of 
papillz, and, usually, a tooth or teeth, and is capable of being 
everted through the mouth until the tooth (which is a weapon 
of offence and not an organ of mastication, being furnished 
with a poison-gland) is thrust out in front in a line with the 
long axis of the body. On this follows a region—the gizzard 
(g.)—distinguished by the thickness of its muscular wall, suc- 
ceeded by the glandular region into which one or more pairs 
of ceca (c.) open, and this in turn is followed by the intestine 
(2.), which forms by far the longest portion of the canal. 
It is with the structure of the third of these regions—that 
which I call here the gizzard—that the present paper is con- 
cerned, a careful examination of the structure of that organ in 
several species having shown that it has been totally miscon- 
strued by previous investigators. 
1 * Histoire naturelle des Annélés,’ tome i. 
