unite into one (fig. 145 A). In fig. 145 both the situation and the shape of the two bars is 



represented. Probably the bars consist on the outside of cuticular matter, remaining after 



decalcification, and staining faintly with carmine ; the inner part appears to me to have been 



calcareous. The bars may also be hollow (cf. Thiele 8 fig. 47). Each bar is encircled by a 



cubical epithelial layer, which is likewise surrounded by muscles : protractors and retractors. 



( )f a common epithelial layer surrounding them nothing is perceptible. The glands belonging 



to the penis-spicula are well developed. In fig. 135// they are seen (violet) on the point of 



opening into the covering of the penis-spicula; their course is represented in figs. 136 — 140. 



Fig. 139 shows a small vesicle g, connected with the precloacal organ by means of a little 



tube (fig. 138); g and // unite into one large vesicle g -f- h (fig. 140), increasing in size more 



proximally and dividing into lobes, as in fig. 142 it has been touched more than once. This 



is undoubteclly the gland of the penis-spicula, described by Wirén and Thiele. Fig. 144 B 



represents the structure of its wall : long strongly granular glandular cells, ciliated and with 



oval nuclei (a) ; at different points the granules increase considerably in number and stain 



intensely with carmine, the whole of the cells becoming dark-red (6). These granular cells are 



especially tound in vesicle g. After g and // have united this difference becomes evident, but 



more proximally cells, more granular, are intermixed with cells less granular. Here and there 



the cells open and the granules are discharged into the lumen of the gland. What kind of 



organ may this be ? Wirén and Thiele look upon the penis-spicula as being in some way 



connected with the copulation, a view which to me too seems correct ; the function of f 



however cannot be made out. The spermatozoa from the precloacal organ might pass throuo-h 



g and // and then go to the penis-spicula; the name of the latter would be the more justifiable 



on this account. Besides its secretory function the gland might also perform the office of 



vesicula seminalis, the size and width of the gland favouring this view ; the .secretion mio-ht 



procure enveloping matter for the spermatozoa. This may to a certain extent also explain the 



fact of the spicula being hollow. Evidence against this view is the presence of numerous 



spermatozoa in the precloacal organ, whereas in g they are entirely absent. Another inter- 



pretation is this; in the gland a secretion is formed, partly conveyed to the penis-spicula, partly 



to the precloacal organ, which is confirmed by the presence of obviously staining granules in 



the precloacal organ and in tube g. 



Hemimenia is, no doubt, closely related to Neomenia. Yet I feel justified in considering 

 it another genus on account of the structure of the integument, which differs very considerably 

 from that of Neomenia. Neomenia belongs to the forms with thick cuticle, pointed spicula and 

 papillae, (group 1 pag. 21), Hemimenia to those with thin cuticle, flat imbricated spicula, 

 without papillae (group 2). It is therefore a transition-form and as such may be compared 

 with Paramenia. 



Cyclomenia nov. gen. 



Length-index 7. Shape of the body cylindrical, proximally bluntly truncated, clistally 

 narrower and more pointed. Dorsal sense-organ present. Cuticle thick. Spicula pointed and in 



