86 ROYAL SOCIETY OF CANADA 
Californian specimens of À. persona are very 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 my mind, the Acmwa dorsuosa, 
Gould, from Japan. 
Dr. Pilsbry sees a resemblance to persona in the Chilian À. ceciliana, 
D’Orb., and has described an intermediate form as A. subpersona. I 
have never seen this last named shell, the figure 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, | should certainly be 
inclined to give it specific rank. 
301, ACMÆA INSTABILIS, Gould, sp. 
Patella instabilis, Gould, Proc. Bost. Soc. Nat. Hist., vol. ii., p. 150 (July, 1846); and 
U.S. Expl. Exped., Mollusca, p. 346, figs. 454, 454a (1852). 
This is not a common limpet, and it has so far been found living in 
British Columbia only on the west coast of Vancouver Island, where it 
occurs on the stems of Macrocystis. 
A. instabilis 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. AcMÆA mirRA, Eschscholtz. 
Zool. Atlas, pt. 5, p. 18, pl. xxiii., fig. 4 (1833). 
Common at low tide on all our coasts. Often coloured green or 
pink by encrusting nullipore. 
Acmæa 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. 
CRYPTOBRANCHIA, Middendortff. 
303. CRYPTOBRANCHIA CONCENTRICA, Middendorft. 
Patella caeca, var. concentrica, Midd., Bull. Acad. Sci. St. Peters., vol. vi., no. 20, 
p- 319 (November, 1847). 
= Lepeta caecoides, Cpr., Rept. British Assoc., 1863, p. 651 (August, 1864) : 
and Proc. Acad. Nat. Sci. Phila., 1865, p. 60. 
Not uncommon, attached to stones or dead shells dredged at Victoria, 
Departure Bay, Comox and Clayoquot. Also off Metlakatla in twenty 
fathoms, off False Head and in Quatsino Sound (Dr. Dawson). 
For notes on the anatomy of this species and its distribution, and 
