NORWEGIAN OPISTHOBRANCHIATE MOLLUSCA 39 



mined, it occupies the same position as Bergh mentions and 

 forms a wide sac with agglutinated spheroid acini all round, and 

 opens by a subpharyngeal duct into the oral cavity, thus proving 

 to be a ptyaline gland. 



As to the salivary glands, I have found a pair of them 

 opening into the oesophagus shortly above its separation from 

 the pharyngeal bulb. 



The Excretory System. 



The kidney, which occupies the whole dorsal side above 

 the genital organs, is briefly described and figured by Bergh 

 (1888). It forms an entire sac, lobated only at the sides by short 

 rounded pouches, which do not penetrate among the herma- 

 phrodite folliculi. Thus the whole organ is not so greatly rami- 

 fied as generally in the Aeolids (cf. Aeolidia papulosa, Hecht 

 1896)1 and some other more or less allied forms (for inst. Bor- 

 nella, Hancock 1864, Dirona, Mac Farland 1912)2. DqIq agrees 

 with the forms mentioned in having a short and narrow reno- 

 pericardial tube which emanates from the foremost end of the 

 pericard, a little to the left of the anal papilla. Closely to the 

 right of this fundus, the nephroproct is situated in the immediate 

 vicinity of the anus. 



T he Re productive System (fig. 15), 



Alder & Hancock, as well as Bergh, have given some 

 statements and figures concerning the genital apparatus, but, as 

 these are founded on a macroscopic investigation by dissection, 

 they have omitted some details of great importance. To their 

 description of the anatomy Pelseener has, in 1895 added the pre- 

 sence of a prostata, a characteristic, in which he finds a sign 

 of specialization beyond the Aeolids. I have reconstructed the 



^ Contrib. å l'étude des Nudibranches. Mém. Soc. Zool. de France. Vol. IIL 

 2 The nudibranch family Dironidæ. Zool. Jahrb. Jena. Suppl. 15, Bd. L 



