114 Proceedimjs of the Royal Society of Victoria. 



same size but are flat, and occiif in tlie skin, where they 

 seem to take the place of the rod-like bodies of other forms. 

 Voii Graft' states that they are mainly composed of carbonate 

 of lime. 



I have found no rt)d-like bodies in Gconemerfes 

 australiensis. 



k Reproductive Organs. 



Burger* commits himself to the generalisation that terres- 

 trial Nemertines are herma})hrodite, which is somewhat 

 remarkable inasnmch as of the four hitherto described forms 

 two, viz. Tetrastemma agricola and T. rodericanuin, are 

 distinctly stated to have the sexes distinct. In Geonemertes 

 australiensis also we find distinct males and females. 



Females would appear to be much commoner than males, 

 for I have oul}' founcl one of the latter amongst the consider- 

 able number wdjich I have examined n)icroscopically. The 

 single male observed, although sexually mature, was consider- 

 ably below the average size ; but females of equally small size 

 also occur, so that it is impossible to found any generalisation 

 as to diftierence in size of the sexes upon this fact. I have 

 detected no other dift'erence between the two sexes except in 

 the reproductive organs themselves. 



In the female (Fig. 24) we find ova in various stages of 

 development irregularly and thickly scattered along the 

 sides of the body, above the lateral nerve cords and beneath 

 the muscular layers of the body wall. Their arrangement 

 appears to bear no definite relation to that of the diverticula 

 of the alimentary canal, which is also irregular. 



The ova, from a very earl}^ stage in their development, aie 

 enclosed separately in special ca])sules (Fig. 24, c. ov.), which 

 open to the exteiior along the sides of the body by means ot 

 narrow ducts (Fig. 24, sp. d.) which pierce the difierent 

 layers of the body wall. The wall of the duct is merely a 

 continuation of the capsule, and around its point of union 

 with the latter there is a large, placenta-like thickening, as 

 shown in the figure. This thickened portion of the capsule 

 is com})osed of a mass of small, granular, nucleated cells, 

 whose boundaries are extremely difiicult to recogni.se. 

 Probably the cells of the capsule, and especially those of the 

 thickened portion, aid in the nutrition of the growing ovum, 



* Op. cit., p. 260. 



