> sorry but Conus tinianus is vormivorous or molluscivorous and in the genus
> dendroconus subgenus ketyconus with other notable cones such as califoricus,
> nigropunctatus , gilchristi and a dozen or so others .
 
My humble opinion only, but I have a large series of gilchristi from Natal
which intergrade fully to tinianus. They are the same species as far as I
can see. Arranged in a row, the pale blue-white of gilchristi is gradually
punctuated with patches of tinianus' patterning until the bodywhorl is
completely covered; spire pattern and early whorl sculpture are identical
in all specimens.
 
In compiling our new Catalogue, the question of the subdivision of the
genus Conus inevitably arose. Here in Japan, they love to split and a
minimum of 15-25 subgenera of Conus is normal. In some cases these are
elevated to full genera (Higo & Goto, 1993 etc.) The splitters will thus
throw up their hands in horror at what we decided to do - the Conidae are
classified in the new work according to Taylor, Kantor and Sysoev's study
of foregut anatomy, and the 'Cone shells' are now the monogeneric subfamily
Coninae. While various methods for subdividing the genus Conus have been
proposed (DaMotta's shell-shape method; Pin and Tack's muscle-scar method
etc.) none of them works for the whole genus, even considered exclusively
on their own terms. Factor in elements which were not considered (DaMotta
did not consider radula morphology or toxin chemistry; Pin and Tack did not
consider anything except scar morphology) and it becomes impossible to
apply these partially-reasoned criteria with any certainty. The genera of
Roeding and Montfort's era (Rollus, Hermes, Cylinder etc. etc.) were
relatively easy to justify with the number of specimens to hand at the
time. Genera created for morphologically similar groupings (Dendroconus,
Virroconus, Turriconus etc) become harder and harder to support as the
number of species known increases, a sure sign that the original criteria
are suspect. As anyone who compiles series of the same species from various
localities will probably admit, the Cones are very prone to form
populations with distinctive characteristics (the huge but paper-thin C.
textile of northwestern Thailand compared with their fat, thick and heavy
sisters from Wakayama and the Sinai; the very thick, gnarled and almost
patternless C. miles of the Amami islands compared with the thinner, more
delicate shells of the Philippines; the small, peach-coloured C. coronatus
of Tanegashima compared with the huge, blue-grey specimens of northern
Queensland etc.) and each newly-discovered population nibbles away further
at the foundations of the various classifications.
 
Some folks find the idea of a single genus with 600-plus species an offence
to their sense of order; there is apparently a feeling that each genus can
only reach a certain size before it must be divided (the same mentality is
often seen at work in the subfamilies of the Buccinidae). I suspect that
sooner or later it will be possible to divide Conus on the basis of an
easily-verifiable criterion, but so far I can't see one. What do Conch-L
people think? One genus or many? If many, then how many?
 
 
PC.