52 ROYAL SOCIETY OF CANADA 
CRYPTOMYA. Conrad. 
114. Crypromya CALIFORNICA, Conrad, sp. 
7 
Sphenia Californica, Conr., Journ. Acad. Nat. Sci. Phila., vol. vii., pt. 2, p. 234, 
pl. xvii., fig. 11 (1837). 
A very common shell in this province. It is found on muddy 
shores between tide marks. 
MYA, Linne. 
115. Mya TRuNcATA, Linne. 
Syst. Nat., ed. xii., vol. i., pt. 2, p. 1112, no. 26 (1767). 
This common European shell is generally distributed throughout 
the province. It prefers a muddy rather than a sandy shore and is not 
contined to the beach but is often found in deep water. It is a common 
fossil in the Boulder Clay. 
Mya precisa, Gould described from Puget Sound, is said by Car- 
penter to be a synonym of this species, but other authors refer it to 
M. arenaria. (ould’s description would answer well for a young speci- 
men of the latter, the original figure I have not been able to see. 
116. Mya ARENARIA, Linne. 
Syst. Nat., ed. xii., vol. i., pt. 2, p. 1112, no. 27 (1767). 
This species is a puzzle to me. Ifit is the M precisa of Gould, or 
if as Dr. Newcombe asserts it is a frequent fossil in the Boulder Clay it 
must of course be considered a native of the province. On the other 
hand, although I had searched the beaches near Victoria for several 
years previously, I never found a specimen alive or dead until 1888, in 
which year I dredged a few specimens of the fry in Departure Bay. 
On my return to Victoria in 1890, after an absence of two years, I 
found M. arenaria in thousands in the very spots that I had searched 
over and over again in previous years and in which it could hardly 
have existed without my finding it. 
So that whether M. arenaria is a native or not, | am fully persuaded 
that the thousands of specimens now living in every sandy shore from 
Victoria to the northern extremity of Vancouver Island are descendants 
of specimens introduced within the last few years. There seems to be 
pretty good evidence that M. arenaria was introduced near San 
Francisco with oysters from Eastern America (for as is well known 
M. arenaria is a very common Atlantic shell), and has multiplied pro- 
digiously, and possibly it has spread up the coast until our province 
was reached some four or tive years ago, 
