Mizuhopecten yessoensis is currently the subject of aquaculture work in western North America.  It is native to the northeast Pacific, from Russia to Japan.

Patinopecten caurinus is native to the eastern and western North Pacific.  It is moderately closely related to M. yessoensis, but the two lineages have been separate at least since the Miocene.

Thus, yessoensis and Patinopecten are both available in western North America, but they are not the same thing.

Coan et al. gives plenty of information; the taxa are listed in Turgeon et al., 1998.

    Dr. David Campbell
    Old Seashells
    University of Alabama
    Biodiversity & Systematics
    Dept. Biological Sciences
    Box 870345
    Tuscaloosa, AL  35487-0345 USA
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That is Uncle Joe, taken in the masonic regalia of a Grand Exalted Periwinkle of the Mystic Order of Whelks-P.G. Wodehouse, Romance at Droitgate Spa