>From: Alan Gettleman <[log in to unmask]> >Reply-To: Conchologists of America List <[log in to unmask]> >To: [log in to unmask] >Subject: Re: Unknown freshwater unionids >Date: Sun, 21 Dec 2003 16:02:51 -0500 > >Jack, >Probably not a freshwater unionid, but Corbicula fluminea, an exotic species form Asia that has in the last sixty years invaded much of the U.S.  When it occurs it can occur in large numbers and especially in artificial impoundments.  I don't remember finding any in southern California, but I have found them in improbable western locations such as Lake Mead in Nevada and some of the very small water courses such as Indian Bend Wash in Tempe, Arizona, where you would not expect to any freshwater shells.  Check Kevin Cummings' picture at: http://www.inhs.uiuc.edu/cbd/musselmanual/page174_5.html  They can get considerably larger than the 1.5" than Kevin indicates, but they are more commonly the size of your shells.  Also the shells are often a lighter and more uniform greenish/olive yellow than the illustration.  Because river sand is often used in the mid-west and south for concrete, often these shells will get mixed in, and I have seen many sidewalks with the half shells or shell imprints on this species on the walk surface. > >Alan Gettleman >Merritt Island, FL >   ----- Original Message ----- >   From: Jack Donner >   To: [log in to unmask] >   Sent: Sunday, December 21, 2003 11:05 AM >   Subject: Re: Unknown freshwater unionids > > >   I was north of Los Angeles, and collected on land, fresh water clams, about 1/2 to 3/4 inch across the width, white with a blue vertex (outside coloration).  Any suggestions what I found?  Thanks,  Jack Donner  [log in to unmask] >