Identifying mollusks from web pictures (and popular booklets) is very
problematic.  I am not a marginellid specialist but the literature does
appear to be confusing.  For many years P. tessellata (Lamarck) was thought
to be a Western Atlantic species.  Persicula accola was described by Roth &
Coan, 1968, for the Panamic species.  Later, P. tessellata was found to
actually be a Panamic species and now the question is, as you point out,
whether or not it is specifically (or subspecifically) distinct from P.
accola.  When Roth & Emerson in 1982 discovered the correct location for P.
tessellata, they wrote a paper on various species of Persicula. Roth and
Emerson describe differences between the two and indicate that they come
from different depths and bottom conditions. Their paper ends with the
statement: "In summary, Persicula tessellata (Lamarck, 1822) and Persicula
accola Roth & Coan, 1968, are similar eastern Pacific species occurring in
then same part of western Panama."

Sorry I cannot be of more help.

Dick Petit

----- Original Message -----
From: "Cecil Bankston" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Saturday, August 06, 2005 11:44 AM
Subject: Persicula tessellata/accola


> How does one distinguish between Persicula tessellata and P. accola?
>
> Are both valid, full species?
>
> The Marginella book shows accola as a form of the variable tessellata
> but doesn't describe its distinguishing features.  Most listings on the
> WWW show accola as a full species.  Some WWW pictures of "accola" look
> essentially identical to others labeled "tessellata."
>
> If any Cystiscidae experts can clarify this mess, I would greatly
> appreciate it.
> --
> Cecil N. Bankston
> Baton Rouge, LA
> USA
>
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