20 



The jjart next to the radula, is of a similar structure. It finally unites with the proximal 

 dorsal coecum which is of considerable size, to form the intestine. We cannot speak of an 

 oesophagus, the whole region from the mouth-cavity to the intestine having the same structure 

 throughout. This is also evident from the glands, merging into it everywhere -, they are strong, 

 pear-shaped glands, opening out between the cells of the pharynx (fig. 91). 



In one of the species the intestine is entirely filled with remains of food, showing clearly 

 that it feeds on animal-food (small Vermes?), even on animals of tolerably large size; the alimentary 

 canal is very elastic, which is also confirmed by the strongly folded wall of the pharj-nx. 



As regards the nervous system, I will only mention that the commissures between the 

 ganglion posterius superius and the ganglia posteriora inferiora are absent. 



Fig. 93 gives a representation of the structure of the generative organs and of the 

 pericardium, figs. 94 — 99 representing schematic sections. The structure of the cloaca-ducts 

 corresponds to that of Proneomenia Weberi; the receptacula seminis are stalked vesicles, but 

 the vesiculae seminales are absent. Both specimens are young, the generative organs are not 

 yet fully developed, whence a uniform structure of the cloaca-ducts and the absence of a 

 glandular part. Both cloaca-ducts coalesce and the precloacal organ merges into the cloaca, 

 which enwraps it in two folds (fig. 95). The coalescence of the cloaca-ducts and the presence 

 of the receptacula seminis prove the animals to be half-grown. The cloaca itself is a wide, open 

 space, narrowing proximally. 



What is of great importance is, that in the cloaca gills are found, 20 in number (fig. 94). 

 They are strongly folded evaginations of the cloaca-wall, coated with cubical ephithelium and 

 strongly ciliated. They are verj' full of blood-corpuscles: at the base of each gill-fold a large 

 blood-sinus is present. For this reason it presents great affinit)' to Paramenia sierra and impexa 

 (Pruvot 4). It is without doubt here that the gills are not evaginations of the rectum-rtall as 

 is the opinion expressed by Wiren for Neomenia, (Wir£n 6'^), cf. figs. 94 — 96; it is seen that 

 the rectum merges into the cloaca far more proximally, the cloaca-wall of the interjacent region 

 being smooth and without gills (fig. 95). Muscular fibres, running in every direction connect 

 the gill-carrying epithelium with the body-wall. Around the gill-folds numerous sharply bordered 

 blood-sinuses are met with ; more proximally all these sinuses unite into a few large ones 

 (fig. 95); more proximally .still there are only 4 sinuses: i on either side of the intestine and 2 

 dorsally from the pericardium, leading the blood from the gills directly into the heart (fig. 96). 

 The latter is composed of an atrium and a ventricle. Fig. 100 gives 5 sections through 

 the pericardium and through the heart. In .-7 the two pericardial offsets are seen, not yet 

 united; the two invaginations going to form the atrium more proximally, are distinct; in each 

 of them one of the above-mentioned gill-sinuses opens (o-, s.). B shows the atrium large and free 

 from the dorsal pericardial wall {a). In C the ventricle appears, in connection with the atrium 

 through an opening; the wall of the ventricle is thick (D) and only far more ])roximally (E) 

 it is ]jroved to be an invagination of the dorsal jjericardial wall. The dorsal blood-sinus is 

 already visible in /f. 



The place of this form is difficult to fix. The body-investment resembles that of Proneo- 

 menia, as well as the radula (cf. Proneomenia neajtolitana, Thif.le 8, fig. 78). But in Proneomenia 



