Some precisions :H. major 's distribution range  only partly includes the
one of H. davidis and it is only where the ranges overlap that    H. major
and H. davidis are sympatric .The blotch on the parietal wall  is always
clearly individualized . Otherwise the specific features assigned by Rehder
to H. davidis
----- Original Message -----
From: "Marlo Krisberg" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, June 01, 2001 2:30 AM
Subject: Re: Harpa major v. Harpa davidus


> Sure sounds good to me.  I always favored Rehder's characterization of
> davidis (The Family Harpidae of the World, Indo-Pacific Mollusca, vol. 3,
> no. 16, November 27, 1973), but with time and more specimens I've come
> around to your view.  The real problem has been finding enough specimens
> from the Bay of Bengal to make a good analysis.
>
> Marlo
>
>
> -----Original Message-----
> From: Conchologists of America List [mailto:[log in to unmask]]On
> Behalf Of Paul Monfils
> Sent: Thursday, May 31, 2001 8:01 PM
> To: [log in to unmask]
> Subject: Re: Harpa major v. Harpa davidus
>
>
> I have also puzzled over this davidis/major thing in years past, but
> after examining hundreds of specimens from a variety of localities, I
> have yet to see a specimen which was sufficiently different from the
> typical range of variation of Harpa major to justify calling it by a
> different name.  My experience has been identical to that of Mr. Frydman
> - some specimens have a single large ventral blotch, some have the
> blotch divided by a light band, forming 2 blotches, and others have two
> light bands, separating the dark blotch into three.  However, I don't
> think this justifies the statement "H. davidis always has three separate
> blotches when H. major can have one or two".  If the shells are
> otherwise identical (or show a similar range of conchological
> characteristics), then it seems to me the more valid statement would be
> "this species can have one, two, or three ventral blotches".  Why give
> the specimens with three blotches a different name?  If that is valid,
> then shouldn't the 1-blotch and 2-blotch forms have separate names as
> well?  Color markings, in the absence of other significant morphological
> differences, are not valid grounds for taxonomic separation.  So, until
> additional evidence comes my way, I consider Harpa davidis at best a
> color variation of Harpa major, but more likely just a synonym.
>
> Paul M.
>