[TAYLOR] MARINE ]MOLLUSCA 85 



Dr. Dull unites A. patina with the Atlantic A. festudinalis. of Muller 

 (Prodr. Zool. Dan., p. 237, 1776), but Pilsbiy, and with him I agree, 

 considers tliat as the Pacitic shell is in nearly all its variations readily 

 distinguishable from its Atlantic analogue, there is no good purpose to 

 be served by dropping our west coast name. 



A. patina is extremely abundant in this province and verj^ variable. 

 I have collected and carefully studied many thousands of specimens and 

 1 am not even yet quite satisfied that we ai-e not now erring in unitiu"- 

 forms that are specifically distinct, as we erred before b,y indulging in 

 exces.sive subdivisions. 



A small deep water variety? of patina \!^ no larger than and has 

 somewhat the shape of A. oirginea. A narrow and compressed variety 

 occurring of leaves of Zostera at extreme low tide, seems to represent 

 the Atlantic A. alveus, Conrad. Giant specimens found between tide 

 marks sometimes attain a length of nearly three inches. 



Jn nearly all our Vancouver Island localities two forms, very 

 different to each other, exist side by side. The one is large and flat 

 with an open colour pattern, the other more conical, darker in colour 

 and with the markings much more delicate and close. This last is 

 evidentl}^ the A. scutum of Eschscholtz, and in some of its varieties can 

 hardly be distinguished from the Chilian A. scutum of D'Orbigny. Near 

 Victoria it is rare to find a specimen that cannot at once be referred 

 to the one or the other of these two forms. 



Dr. Jeffreys (in a paper which I have referred to undei- Modiolaria 

 marmorata) speaks of this species as being very common in Japan, where 

 however I do not think it occurs at all. 



The variety ochracea. Dall, described from Monterey, is credited to 

 Vancouver Island by Dr. Pilsbry, but I have never seen a native specimen. 



2911. AC.M.KA I'ELTA. EschsclloltZ. 



Zoo]. Atla.s, pt. 5, p. 19, no figure {\S;V6). 

 + A. cassis, E.sch, Zool. Atlas, pt. .5, p. 19, pi. x.xiv, fitc. "i (IS;«). 

 etc., etc. 



This species is almost as common as A. patina. It is very variable 

 but it does not approach the last named in any of its forms. In the 

 adult shells the interior is often entirely white, but there is a curious 

 variety m which the interior is marked with numerous and close raised 

 lines of purplish brown radiating from apex to the edge. 



300. ACM.KA PKKSONA. KschsclloltZ. 



Zool. Atla.s, pt. 5, p. 21), pi. .xxiv.. tig-.s. 1 and 2 (l!-:«). 

 + f/igifalis, E.sch., etc., etc. 



Tins IS a smaller s|)ecies than either A. patina or A. pelta, and is not 

 quite so common. It is geuei-ally found very near high-water mark, and 

 consequently it must spend much of its time out of water. 



