NORWEGIAN OPISTKOBRANCHIATE MOLLUSCA 13 



Eliot (1910) hesitates to adopt my opinion as to the two 

 forms in question. „An examination of further specimens seems 

 desirable before the place of these forms is fixed" (p. 167). In 

 the following pages I will give a more detailed description of 

 the internal anatomy of Goniaeolis typica M. Sars, and on the 

 base of it I will try to state its affinities among the Nudibranchia. 



Anatomy of Goniaeolis typiea M. Sars. 



The following accounts are based on a specimen from 

 Skagerrack and belonging to Riksmuseum, which was sectioned. 



The Intestinal Canal. 

 The large and muscular pharyngeal bulbus (fig. 6, ph.) is sur- 

 rounded by ovoid jaws without masticatory processes (for their nearer 

 form cf. Sars) and a conical snout (fig. 4). The labial disc (fig. 5.) 



Fig. 4. G. lobata, pharyngeal bulbus Fig. 5. Labial disc of G. lobata 

 (cf. p. 46). (cf. p. 46). 



is furnished by a circle of radiating folds and armed by a strong cuti- 

 cular covering, thickest at the sides of the mouth. On the upper side 

 of the pharynx emerges the narrow short oesophagus, surrounded by 

 the nervous centre and flanked by the salivary glands. The oeso- 

 phagus extends backwards on the upper side of the pharynx, in the 

 beginning between the jaws. At the point where it separates 

 from the bulb, the buccal ganglia are situated. Farther back- 

 wards, having passed the nervous ring, the oesophagus suddenly 

 debouches into the sac-formed stomach (fig. 6, s). The radular 

 sac ends at the nervous centre as well. The stomach has simple 

 walls lined with a cubic epithelium. In the posterior part of the 

 stomach a broad liver duct debouches, with regularly folded 



