Dear Allen,
In normal number of whorls are quite important and sometimes can vary a
little in a type series. What i asked was how can we count 1/4 whorls when
aperture of a spire-shaped shell is turned to you....
best regards
Ümit
----- Original Message -----
From: "Allen Aigen" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, February 22, 2005 7:00 PM
Subject: Re: counts
> Umit,
> It might be interesting to precisely measure large populations of
> representative species and see if it makes a difference if the holotype
> is 11 or 11 1/4 whorls. I would suspect that the population of mature
> specimens would be best characterized by a range of sizes (mean and
> standard deviation might also be useful) which would be a better way to
> describe the species than the precise number of whorls on the holotype.
> Of course, if the number is constant within a population, that is
> important to note.
> Allen Aigen NYC
> [log in to unmask]
>
>
>
> On Tue, 22 Feb 2005 10:22:20 +0200 umit <[log in to unmask]> writes:
> > Thanks for all remarks. As indicated by Aydin Orstan and David
> > Campbell one
> > (me) has to standardize his method, that is ok. but say if is a new
> > species
> > figured only by genitalia and a photo who can understand it (whether
> > a
> > particular method is applied)? Actually, in almost none of the
> > landsnail
> > papers i read includes such an info...An example for the problems
> > this can
> > cause, when you inspect Vitrea species in Schütt (2001) "Die
> > Türkische
> > Landschnecken", when you compare figures and text you can see that
> > both
> > methods i wrote were applied to separate species (see V. contracta
> > and V.
> > heniae, lodosi....)
> >
> > My problem with the slender and tall shells, like an Ena, is that
> > how one
> > can say that there is 11 1/4 whorls if the general practise is to
> > count in
> > 'vertical' way...
> >
> >
> -------------------------------------------------------------------------
> ---
> > --------------------------------------------------
> > In Aydin's paper there is a discussion about the identity of
> > circular hole
> > drillers in landshells...in this list once was a discussion about
> > oval or
> > circular holes to identify the predator. Can carnivorous mollusks be
> > the
> > reason for very small circular holes in land snails? For superficial
> > perfectness of the circles in shells, i harldy can think that heavy
> > mandibles can do it. maybe there is a group of small endoparasite
> > worms of
> > alimentary canal(?) chemically dissolve shell or a heteropteran
> > sting bug
> > penetrate the shell (latter seems more irrational).
> >
> > And i wonder if Lampyris-type snail specialists bore shells
> >
> -------------------------------------------------------------------------
> ---
> > --------------------------------------------------
> >
> > Ümit
> >
> >
> > ----- Original Message -----
> > From: "aydin" <[log in to unmask]>
> > To: <[log in to unmask]>
> > Sent: Tuesday, February 22, 2005 4:29 AM
> > Subject: Re: counts
> >
> >
> > > Ümit,
> > > There is no one standard whorl counting method. I prefer to count
> > along
> > the
> > > suture, which gives 1/2 whorl more than does omitting the first
> > semicircle.
> > > There are other ways of doing it. I don't think anyone can
> > reasonably
> > argue
> > > that one particular method is the "right" way of doing it. Just
> > explain
> > how
> > > you did it if you write a paper.
> > >
> > > An easy way to count the whorls of clausiliids & other tall shells
> > is to
> > > start from the aperture & go backwards; the body whorl will be #1,
> > > penultimate whorl #2 & so on. This is useful if you only need to
> > refer
> > > especially to the lower whorls for whatever reason (see my paper
> > on drill
> > > holes in Turkish land snails).
> > >
> > > Aydin
> > >
> > > On Mon, 21 Feb 2005 09:55:04 +0200, umit <[log in to unmask]>
> > wrote:
> > >
> > > >Dear all,
> > > >
> > > >I noticed a difference in counting whorls when reading Likharev
> > and
> > > Rammelmeier (1952) "Lands Snails of....USSR" book. Normally when
> > counting
> > > whorls a -the first- semicircle of embyronic turn is omitted and
> > 360
> > dgress
> > > afterwards is accepted as 1 turn, so that 1st turn counted
> > resembles
> > > profile of a Nautilus. But in that book, i think, the semicircle
> > is not
> > > omitted and 1st turn counted ends where parallel to the median
> > line of the
> > > semicircle passes (total count is 1/2 turns less than the former).
> > Is
> > there
> > > any other applications?
> > > >
> > > >The other question, when counting clausiliids a practical method
> > is to
> > > count whorls from the frontal view, i.g. mouth facing you. How do
> > you
> > count
> > > similar slender snails like Subulinidae etc.?
> > > >
> > > >
> > > >Best wishes
> > > >
> > > >Ümit
> > > >
> > > >
> > > >
> > >
> > >
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