164 Transactions of the Royal Canadian Institute 



to be of a "yellowish white slightly translucent" whereas in the specimens 

 I have seen alive it was quite white without a trace of yellow. Through 

 the skin of the dorsum a network of spicules can be distinguished appear- 

 ing as interlacing white lines. The clavus of the rhinophores is a deep 

 orange red and the branchial plumes are tinged with the same colour. 

 The tips of the papillae are also of the same deep orange red save for a 

 terminal spot of light orange. 



Dimensions. — ^The largest specimen examined measured 18 mm. long, 

 5 mm. broad and 5 mm. high. 



Head. — 'The head is relatively large and broad, being carried forward 

 into a sort of veil bearing papillae similar to those on the dorsum but 

 not as big as the largest of them. The mouth opening is conspicuous 

 with fleshy folded lips. The laterally placed tentacles are sub-cylindrical 

 about 1.5 mm. long and have a groove along their upper surface. Just 

 above the point of origin of the tentacles and running parallel with the 

 mantle edge is a small but distinct sub-pallial fold which passes back 

 along the head and a short way on to the body. 



Foot. — 'The foot is elongated and fairly narrow, almost square in front 

 where it is bilabiate with a projecting upper lip slightly concave. The 

 margins are fairly broad and thin. 



Rhinophores. — 'The rhinophores are completely retractile into a deep 

 sheath with a quite smooth rim. The stalk is cylindrical and the per- 

 foliate clavus slightly enlarged and tapering, of a deep orange colour 

 and bearing 12-14 leaves. 



Branchiae.- — -The five tripinnate branchial plumes are not retractile 

 and arranged in a incomplete circle. They may be tinged with orange 

 red. Within the circle lies the distinct anal papilla to the right of which 

 is the sm!all renal opening. 



Radula. — ^The radula is colourless, has a wide median groove and a 

 very characteristic shape. The teeth are arranged in 74-80 rows. The 

 rachis possesses a series of oblong plates which in the specimens I have 

 examined are relatively longer and more regular than figured by MacFar- 

 land. The first pleural tooth is a small longish structure, thin and curved 

 with a small hook at the end. The secon4 pleural tooth is strong, stout 

 and of irregular form. At the upper end it bears two broad short claw- 

 like processes, one directed inwards and the other outwards. The median 

 part also has a strong thickened band. The other lateral teeth number 

 from 10-14, are roughly diamond shaped with curved sides and they are 

 closely imbricated forming a sort of pavement. The inner teeth bear 

 two small points at the upper corner but these are lacking in the outer- 

 most teeth which are also less strongly developed. 



