Martin,
 
Suggest you compare your shell from Panama carefully to "Typhis
latipennis Dall, 1919" which ranges from the Gulf of California to Panama
Bay, according to Keen (1971).
 
The original description of "Talityphis perchardei" is in Radwin and
D'Attilio's Murex Shells of the World (1976).  Following a lengthy
description, the authors cite collecting localities in Trinidad and
Surinam.  They also note: "...this species (perchardei) must be
considered a Caribbean cognate of the Panamic T. latipennis (Dall,
1919)."  In light of this, it looks like what you have is most likely a
T. latipennis rather than a range extension for T. perchardei.
 
Hope this information helps.
 
Bill Fenzan
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