12 



and divided into two halves by a median fold of the dorsal wall. In the distal portion of the 

 "Flimmerhohle" the wall is built up of cylindrical epithelium with long cilia and strongly granular 

 cytoplasma. More proximally this epithelium changes into a cylindrical epithelium, carrying cilia, 

 but staining with difficulty, and remaining very transparent; the nuclei are spindle-shaped and 

 the cells are of a thread-like structure. This region produces a secretion, similarly clear and 

 transparent. This is the "vordere Bauchdrlise" with its secretion, which is found around the 

 organs everywhere in the anterior part of the body. The "hintere Bauchdrlise" is also well 

 developed and its pear-shaped, glandular cells, staining bright red with carmine are found 

 amone those of the "vordere Bauchdrlise". 



A very small dorso-terminal sense-knot occurs at the very hinder extremity of the animal. 

 The alimentary canal furnishes some peculiarities, cf. fig. 43, reconstructed out of trans- 

 verse sections, and the schematic sections figs. 44 — 47. The cavity a may apparently be 

 compared with the mouth-cavity of the other Neomeniidae. Here the numerous cirrhi cjccur 

 again and also the ciliated "Mundleisten". However the cavity does not lead directly into the 

 pharynx : the proper entrance into it is found in cavity 5. Both cavities a and d are separated 

 from each other bv a fold (fig. 450- ^^ does not give the impression that this fold occurs 

 here casually ; a strong muscle proceeding transversally is found in this fold ; moreover a number 

 of muscular fibres, taking their course diagonally, attach themselves to it. I look upon the 

 tolerably perfect separation between the anterior part of the mouth-cavity, which carries organs, 

 and that part, in which the opening of the pharynx is found, as an arrangement, the animal 

 can use at will. Cavity d does not carry any organs. 



The pharynx itself has a thin folded wall ; it runs dorsally and takes up a wide coecum, 

 directed proximally, the wall of which is folded too. An extremely thin circular muscular layer 

 surrounds the wall of the pharynx. 



The radula may easily be discerned. It consists of about 5 rows of teeth behind each 

 other. Such a row consists of two large teeth; fig. 49 A represents a whole tooth; B is the 

 upper side of another tooth, C its lower portion. It is evident that regarding the exact structure 

 of the teeth no perfect certainty is obtained. This radula however is distinct distichous, every 

 row consisting of two teeth of shape A, operating as a pair of scissors. So that there is an 

 affinity with Paramenia, Lepidomenia and Ismenia. But in none of these forms does the radula 

 seem to be so strong as it is here, where about 5 pairs of such strong radula-teeth occur. 



The typical distichous character of the radula is evident from the radula-sac; in following 

 the radula in distal direction we reach the radula-sac, consisting of two pouches, in each ot 

 which a tooth is formed ; only more proximally a single radula-sac originates from the coalescence 

 of these two pouches (fig. 50). 



The radula teeth are placed upon an epithelial layer with round nuclei, tolerably strong 

 muscles attaching themselves to this. Immediately close to it the salivary glands open out; they 

 are long and take their course ventrally from the intestine (fig. 48). To the right and left ot 

 the radula-sac some large cartilaginous cells are found (fig. J,-jcc), serving fi)r support to the 

 above mentioned muscles. Around the two salivary glands and against the wall of the intestine 

 a peculiar glandular tissue is found : unicellular strongly granular glands, grouped in lobes. They 



