On an Australian Land Nemertine. 121 



Fkj. 17a. — A single stylet, drawn under the same conditions. 



Fig. 176. — Head of a stylet, seen end on, drawn under the 

 same conditions. 



Fig. 1 7c. — Probable mother cell of a stylet, from one of the 

 reserve sacs, drawn under the same conditions. 



Fig. 18. — Small j^ortion of a section from the same series as 

 Figs. 2-6, taken a little to one side of the middle 

 line, between the sections represented in Figs. 

 5 and 6 ; to shew the cui'ious cellular plug in 

 connection with the median vessel and projecting 

 into the cavity of the proboscis sheath. Drawn 

 under Zeiss D, oc. 2, camera outline. 

 c. pi. Cellular plug. 



(Other lettering as before). 



Plate X. 

 Fig. 19. — Portion of the system of excretory tubules, from 

 above the proboscis sheath in a transverse 

 section stained with haematoxylin. Drawn 

 under Zeiss F, oc. 2. 



Fig. 20.^ — Posterior portion of median vessel, as seen in 

 longitudinal section stained with hsematoxylin. 

 Zeiss F, oc. 2. 

 cr. Concretion (?) within the ves.sel. 



Fig. 21. — Portion of median vessel seen in a transverse 

 section stained with hrematoxylin, shewing one 

 of the lacunar dilatations. Zeiss F, oc. 2. 



c.m.v. Circular muscle fibres around the vessel. 



l.m.v. Lacunar dilatation of the vessel. 



nil. V. Nuclei of the inner wall of the vessel. 



ves. c. Vesicular cells outside the vessel. 



Fig. 22. — Transverse section of the median vessel. Zeiss F, 

 oc. 2. 



(Lettering as before). 



Fig. 23. — A lacuna on the lateral vessel with an excretory 

 tubule opening into it. From a transverse 

 section stained "with h?eraatoxylin. Zeiss F, oc. 2. 

 I. I. V. Lacuna on the lateral vessel. 

 fOther lettering as before). 



