You might try contacting Paul Valentich Scott at the Santa Barbara Museum of Natural History.  I don't know his email but the Museum web site is http://www.sbnature.org
On Aug 2, 2010, at 12:49 PM, Charles L Powell wrote:

> I'm working on some middle Miocene fossil mollusks from southern Orange
> County, southern California and have an internal mold that matches in shape
> fairly well with Protothaca costellata (Sowerby) illustrated in Axel A.
> Olsson (1961, Mollusks of the tropical eastern Pacific. Panamic-Pacific
> Pelecypoda: Paleontological Research Institute, Ithaca, pl. 49, f. 3).  But
> I can find no further record of that species in Olsson or elsewhere.  Any
> help running down the species name or what that species is now called would
> be appreciated.
>
> Best,
>
> Chuck
>
> Charles L Powell, II
> Western Earth Surface Processes Team, MS 975
> U. S. Geological Survey
> 345 Middlefield Rd.
> Menlo Park, CA  94025
> [log in to unmask]
> (650) 329-4985
> https://profile.usgs.gov/professional/mypage.php?name=cpowell
>
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