174 Transactions of the Royal Canadian Institute 



rhinophores and radula also differ not only from that species but also 

 from any others that have been described previously. It is therefore 

 listed here as a distinct species under the Acanthodoris nanaimoensis. 



Habitat. — The individuals of this species were obtained in April from 

 the rocks of Jesse Island and also from the Lagoon near Hammond's 

 Bay. It is apparently not common since it had not been collected 

 previously and only four specimens were obtained. 



Genus Lamellidoris (Alder & Hancock). 



Lamellidoris Alder and Hancock, Brit. Nud. Moll. Pt., VII, 1855, p. 42; 

 Bergh. Syst. der Nudibr. Gstero., 1892, p. 155-165; Proc. Acad. Nat. 

 Sci. Phila., 1879, p. 211-216; Bull. Mus, Comp. Zool., Harvard, p. 

 191; Eliot. Brit, Nud. Moll., Pt, VIII, 1910, p. 155. 



The dorsal surface is granulate or tuberculate; the margins of the 

 rhinophore openings are smooth. The head is broad, crescent-shaped 

 with the comers produced into tubercular processes. The branchiae are 

 simply pinnate,, rather numerous and set in a horse shoe. There is no 

 regular labial armature, but the oral cuticle is armed with a ring of 

 papillae and two ridges. The radula is very narrow, consisting only of 

 two teeth on each side of the rhachis, the inner large and the outer small. 

 There is sometimes a rather imperfectly formed median tooth and some- 

 times none at all. 



Lamellidoris bilamellata (Linnaeus). 



Doris bilamellata Linnaeus, Syst. Nat., 12, Ed. v. i, p. 1083. 



Doris bilamellata Alder and Hancock, Brit, Nud, Moll,, Pt. VI, 1984, 



Fam. I, pi. II. 

 Lamellidoris bilamellata (L) var pacifica Bergh. Proc, Acad, Nat. Sci. 

 Phila,, 1880, p. 62, pi. v.; Bergh, Bull. Mus. Comp. Zool., Harvard, 

 p. 192. 

 Lamellidoris bilamellata Eliot, Brit. Nud. Moll., pt. VIII, 1910, p. 156. 



The full synonymy of this species is given in Alder and Hancock 

 (/. c.) and so need not be repeated here. 



Body. — ^The body is sub-elliptical slightly broader in front than behind, 

 and it is somewhat flattened. The dorsum is covered with tubercles of 

 varying size they reach their maximum postero-mesially in the region of 

 the branchiae and are smaller at the egdes of the mantle and anteriorly. 

 The mantle is thickish but not very wide; covering the foot save that the 

 hinder end of the latter protrudes during locomotion. Stout blunt 

 spicules were plentiful in the dorsum and arranged in a radiating manner 

 around the bases of the tubercles. 



