16 NILS HJ. ODHNER 



externally, there is no separating furrow between cerebral and 

 pleural ganglia, and the pedal ganglia are intimately joined to 

 the cerebro-pleural ones, by means of very short externally 

 invisible connectives. 



Fig. 7 shows the nei'ves arising from respective ganglia. 



Whether eyes exist, or not, could not be with a certainty 

 stated, but a vestigial optic nerve (3) was observed on the right 

 cerebral ganglion. A statocyst was also seen on this side. 



Heart, Pericardium and Nephridium. 



These are situated in the median part of the body (fig. 6). 

 Two vessels lead to the auricle from behind, where they arise 

 among the subcutaneous lacunae. From the ventricle an anterior 

 aorta descends behind the transverse portion of the intestine, 

 which it crosses beneath, penetrating towards the front and 

 bifurcating in the vicinity of the root of the penis. Here, it gives 

 off a large posterior trunk which runs backwards in the mus- 

 culature of the penis and the wall of the body; a smaller branch 

 passes on forwards to the hermaphrodite gland, and another 

 vascularises the buccal regions. 



From the right side of the pericardium a funnel descends 

 narrowing towards below. At the bottom of this funnel the 

 pericardial lube {p. t.) of the nephridium emerges, having strongly 

 folded walls lined by an epithelium with long ciliae. The peri- 

 cardial tube is rather long, descends in a coil and opens into a 

 projection towards the front of the nephridium. This anterior 

 lobe communicates farther above with the median sac of the 

 nephridium. The latter forms a thin-walled sac on the posterior 

 side of the pericaridium between the lateral parts of the liver, 

 among which it sends projections, as well as from ils mar- 

 gins; these ramifications, however, are by no means so 

 numerous and delicate as in the Aeolidoidea. From the median 

 sac emerges a small diverticulum on the right side; it forms an 

 urinatory chamber which is produced forwards between intestine 



