98 Proceedings of the Royal Society of Victoria. 



a glandular nature. Possibly, as Biirger suggests,* tbey 

 secrete the material which forms the handle of the stylet. 

 This layer of glandular, deeply staining cells is interrupted 

 by the sacs which contain the "reserve" or "accessory" stylets. 

 These sacs (Fig. 16, s. r. s.) have the apj^earance of iiregular, 

 clear, rounded spaces ; they are not definitely two in number, 

 as appears to be the case in G. chalicopltora, but their number 

 varies : I have counted as many as live in a single specimen. 

 Nor do they appear to be constant in position, although in 

 the section represented in Fig. 10 two .sacs happen to be cut 

 through in a po.sition which seems to have a dehnite relation 

 to that of the poison canal. Each sac contains about four 

 accessory stylets, whose structure will be considered later 

 on. 



Outside the layer of glandular cells is a very thin, 

 uninterrupted layer of longitudinal muscle fibres, followed 

 immediately by a delicate external epithelium, which is 

 extremely difhcult to recognise. I could find no trace of 

 an external circular layer of muscles in the stylet-region of 

 the proboscis. 



Certain structures in the anterior half of the stylet-region 

 require further notice. These are the stylets, the stylet- 

 handle and the poison canal. All these parts may best be 

 studied in a longitudinal section of the proboscis taken in 

 the plane of the central stylet and poison canal. Sucli a 

 section is represented in Fig. 1 5. It will be seen that the 

 stylet-handle is a somewhat pear-shaped structure whose 

 broader end is posterior, while into the narrower end is 

 inserted the base of a stylet, whose apex pi'ojects forwards 

 into the lumen of the eversible portion of the proboscis. At 

 one side of the stylet-handle a narrow "poison canal" Qx d.) 

 leads up from the " poison reservoir" (jx r.) in the posterioi' 

 half of the stylet-region. This poison canal leads up to the 

 base of the central stylet Tlie stylets themselves are sharp- 

 pointed, perfectly transparent needles, about O"! 2 mm. long 

 arid of the shape shown in Fig. 17. Each resembles a nail, 

 with a slightly enlarged head separated from the remainder 

 by a slight constriction. The inner portion appears to be 

 softer than the outer, from which it is pretty sharply marked 

 off, and near the base, or head, is (at any rate in the reserve 

 stylets) a small space, quadrangular in lateral view, which is 



* " Untersnchiingen iiber die Anatomic iind Histdlogie der Nemertinci), 

 <S:c," Zeitsch. fiir wiss. Zoologie, Vol. 50, p. 1, 18'JO. 



