172 Transactions of the Royal Canadian Institute 



cylindrico-conical with a blunt apex and bears 22-26 leaves along the 

 edge of which is a pale yellow or white line. In life they are directed for- 

 wards and outwards. 



Branchiae. — ^The seven branchial plumes are not retractile into a 

 sheath and in life wide spreading. They lie in an incomplete circle within 

 which lies the anal papilla. As noted they are of a yellowish colour par- 

 ticularly towards the tips. 



Radula. — ^The narrow radula is folded to form a deep groove and bears 

 30 rows of teeth. As in other Acanthodorids there are no median teeth 

 and the first lateral is much larger and of a different shape from the 

 remainder. The large tooth has an angular quadrilateral base and a well 

 marked spine. The lower portion of the base is considerably thickened. 

 The spine is strengthened at its origin by a ridge which is continued as a 

 row of 14-17 small denticles. The remaining pleural teeth 6 or 7 in 

 number are quite small elongate and bear a ridge on their outer sides. 

 They are long triangles with rounded comers at the base and decrease 

 in size as they pass outwards. 



The labial armature is incomplete above and composed of a number 

 of small closely packed plates. Below it is transformed into a single 

 concave plate like thickening. 



The genital aperture is high up on the right side of the body below 

 the mantle and behind the level of the rhinophores. The end of the glans 

 penis is furnished with a few minute hooks. 



The species was first described from Monterey by MacFarland (10) 

 who later (11) gave a very good account of its internal anatomy. 



Habitat. — It has been dredged in about 15 fathoms in Nanoose Bay 

 and also collected at False Narrows and Mudge Island but is nowhere 

 common. 



Acanthodoris nanaimoensis sp. nov. 



Body. — ^The body is plump, well arched and almost oval but slightly 

 broader in front than behind. There is a wide moderately thick mantle 

 present that completely covers the foot save for a small tail at the end 

 during active movement. The dorsum is covered with numerous fine 

 closely set conical papillae in a manner typical of the Acanthodorids. 

 On the whole it resembles A. hudsoni in shape save that it is larger and 

 plumper. 



Colour. — The whole of the dorsum is of a pale dusky brownish mauve 

 which causes the white papillae to stand up in marked contrast. The 

 tips of the branchiae are of a port wine red colour. The sides of the body 

 and the foot are of a dull greyish white. Save for the fact that they get 



