NUDIBRANCHS OF THE VANCOUVER REGION I5I 



There is no armature either in the stomach or on the genitalia. The 

 hermaphrodite gland forms a layer spread over the liver." (Eliot i. c). 



Tritonia diomedia Bergh. 



Tritonia diomedia Bergh, Bull. Mus. Comp. Zool., Harvard, Vol. XXV. 

 no. ID, 1894. p. 146. 



Body. — The body is stout and limaciform ending posteriorly in a 

 blunt tail and is approximately rectangular in cross section. The dorsum 

 is fairly flat and smooth reaching its highest point about half way back. 

 A low palHal ridge along each side of the dorsum separates it off from the 

 sides of the body and along the ridge are placed the branchial tufts, 13-15 

 in number. The stout rhinophore sheaths lie just in front and inside 

 the anterior gill tuft. The veil is well developed in the form of two lobes 

 with a notch between them and bears on each side 1 1 small blunt conical 

 papillae and at its postero-lateral edge a fairly broad deeply grooved 

 tentacle. 



The anal papilla is short and lies about half way back on the right 

 side of the body below the gill tufts. Just above it is a minute renal pore. 

 The genital aperture is also on the right side further forward and lower 

 down. 



Colour. — I have not examined this species alive and so cannot describe 

 its colour. When preserved it is of a whitish colour with indications of 

 brownish pigment on the back and sides. Bergh also examined preserved 

 specimens but hazards the suggestion that "Die Farbe des lebenden 

 Thieres ist warscheinlich roth oder purpurroth gewesen". 



Dimensions. — The specimen was only a small one measuring, pre- 

 served, 25 mm. long by ID mm. wide by 8 high, whereas dimensions of 

 the larger of Bergh 's specimens was 60 mm. long by 35 mm. wide and 

 27 mm. high. 



Head.— The head is well developed and broad and its corners pro- 

 duced to form the grooved tentacles already noticed as lying at the 

 posterior border of the veil. The mouth is a longitudinal slit with 

 distinct lips. 



Foot. — The foot is broad and flat ending behind in a blunt tail. In 

 front it is abruptly rounded and bilabiate, the two lips of approximately 

 equal thickness. 



Rhinophores: — 'The rhinophore is retractile within a short stout 

 cylindrical sheath with a practically smooth edge. The clavus bears a 

 crown ol 10 simply pinnate papillae of which the hindermost is the 

 largest. 



Branchiae. — The branchiae are in the form of small branched tufts 



