86 ROYAL SOCIETY OF CANADA 



Californiaii specimens of A. persona are veiy different in appearance 

 to Vancouver Island ones, and might at first sight be considered as 

 belonging to a distinct species. 



The nearest ally of A. persona is, to ni}- mind, the Acnuva dorsuosa, 

 Gould, from Japan. 



Dr. Pilsbry sees a resonblance to persona in the Chilian A. ceciliana, 

 D'Orb., and has described an intermediate form as A. subpersona. I 

 have never seen this last named shell, the tigure of which certainly 

 does look like persona, but I have examined scores of A. ceciliana, and 

 never saw one in the slightest degree approaching our A. persona. If 

 Dr. Pilsbry's A. subpersona is really a Chilian form, 1 should certainly be 

 inclined to give it specific rank. 



301. ACM.KA INSTABILIS. Gould, Sp. 



Patella inslabilis, Gould, Proc. Bost. Soc. Nat. Hist., vol. ii., p. 1.50 (July, lH4fi); and 

 U. S. Exp). Exped., Mollusca, p. ;M6, figs, 4.54, 4.54« (18.52). 



This is not a common limpet, and it has so far been found living in 

 British Columbia only on the Avest coast of Yancouver Island, where it 

 occurs on the stems of Macrocystis. 



A. instabdis has been considered by some conchologists to be only a 

 kelp form of A. pelta, but Dr. Pilsbry with others (myself included) 

 consider this by no means proven. 



302. AcM.EA MiTRA, Eschscholtz. 



Zool. Atlas, pt. 5, p. 18. pi. xxiii., tig. 4 (ISSH). 



Common at low tide on all our coasts. Often coloured green or 

 pink by encrusting nullipore. 



Acma'a scabra, Nuttall, common in California, has been quoted from 

 Vancouver Island, but I have never seen a native specimen, and do not 

 believe that it occurs here. 



CEYPTOBEANCHIA, Middendorff. 

 303. Cryptobranchia concentrica, Middendorft\ 



Piifclhi rnrca, var. covcrntriva, Midd.. Bull. Acad. Sei. St. Peters., vol. vi., no. 20, 

 p. :il9 (November, 1847). 

 = Lepeta caecoiclin, Cpr., Kept. British Assoc, 1808, j). (wl (August, I8<>4) ; 

 and Proc. Acad, Nat. Sci. Phila., 180.5, p, (50. 



Not uncommon, attached to stones or dead shells dredged at Victoria, 

 Departure Bay, Comox and Clayoquot. Also off Metlakatla in twenty 

 fathoms, oft" False Head and in Quafsino Sound (Dr. Dawson). 



For notes on the anatomy of this species and its distribution, and 



