Dear, Paul Monfils
 
        First, I would like to apologise for the delay on my point of view of S.
pectinata and second to thank you for your reply.
        Please correct me If  I'm wrong: Guido T. Poppe & Yoshihiro Goto in there
book European Seashells Vol.I,  refer to S. algesirae (Quoy & Gaimard,
1834) and S. grisea (Gmelin, 1791) as two synonyms of S. pectinata
(Linnaeus, 1758). In the other hand Nobre., 1938-40, "Fauna Malacológica de
Portugal I. Moluscos Marinhos e das Águas Salobras", Porto, 806p. refers
in page 40 that S. algeserae is the specie fond in Portugal and also
recognised in the Cape Verde Islands. This last author also refers as
synonymies S. palpebrum (Reeve) and says that Mac-Andrew mentions this
specie as S. concinna.   
        Consulting Guido T. Poppe home page, he now refers to S. pectinata not as
a synonym of S. algeserae: Siphonaria pectinata C. Linnaeus, 1758 North
Atlantic and Siphonaria algesirae J. R. C. Quoy & J. P. Gaimard, 1829 Cape
Verde. Well what should it be, S. pecctinata or S. algesirae ? 
        In my poit of vew (If we are really only talking of one particular
specie), Linnaeus first identified this specie in the American coast before
Quoy & Gaimard did the same for the same specie that occurred in the
Mediterranean. 
But the doughty remains !! You said in your last e-mail, to a possible
difference between  S. petinata and S. algesirae since you have both to
compare. Unfortunately I only have the specie that occurs here in the south
of Portugal, so the dought remanes !! Is it the one refered my Linnaeus or
by Qouy & Gaimard ? I could send you a couple of preserved specimens from
Portugal if you like ?  
Maybe some one out there can jump on in with there to scents ?  
Thank you once again Paulo on the geographic distribution.
 
        My best regards to Paul Monfils and the hole crew
 
        Wishes of a happy happy Easter
 
        Carlos Afonso