Marlo,

When the periostracum is present, the "shagreen,"
or velvety, texture imparted by the ultrasculpture is certainly enhanced.

I have several specimens that were rendered
decorticate by chemical treatment or wave action
abrasion, and they retain this sculpture. I'm no
expert on this, but it appears to reside in a
shell-layer that is more friable than the rest of
the shell, possibly an intritacalx of sorts.

BTW, the variation of shell form and
(macro)sculpture demonstrated in your web-feature
steels my resolve that the antipodal populations
are conspecific with ours of E Florida and
elsewhere in the Carolinian and Caribbean Provinces.

Harry


At 08:18 PM 12/30/2009, you wrote:
>Harry,
>
>Take a closer look and try scraping a small bit of that ultrafine, even,
>beaded spiral sculpture and I think you may find it is the periostracum.
>Once the periostracum is bleached off the sculpture is as illustrated in my
>presentation at:
>http://z14.invisionfree.com/Conchologist_Forum/index.php?showtopic=1866
>
>I'll do a supplement illustrating the feature you note.
>Marlo
>-------------------------------------------------
>Harry wrote in part:
>
>Costoanachis sertulariarum (d'Orbigny. 1839) and C. floridanum (Rehder,
>1939), remind me of Rodney Dangerfield; they get no respect. Fresh specimens
>of both exhibit an ultrafine, even, beaded spiral sculpture that sets them
>apart from any other columbellid in the western Atlantic. However, the
>original description of neither (text in 1841 for the former) mentions this
>diagnostic character, and Rehder didn't even cite d'Orbigny's taxon when he
>named the latter a century afterward. Even Radwin (1977) overlooked that
>feature on the d'Orbigny species.
>
>The ultrasculpture is well-preserved on most of these shells. Other than a
>tendency for the shells from the four southernmost localities to have grown
>somewhat larger, I see no way to distinguish among the many dozens of shells
>in these sixteen lots. Based on a like assessment a couple of years ago, I
>synonymized the two in print citing Rios (1994) as originating the concept.
>
>Harry
>-------------------------------------------------
>Fabio replied:
>
>Speaking of Rios, in his latest book, Compendium of Brazilian Sea Shells
>(2009), he considers Anachis sertularium as a valid species, and listed the
>following as synonyms:
>brasiliana Martens, 1897
>decorate Strebel, 1905
>floridana Rehder, 1939.
>
>He also notes that A. moleculina Dulcos [sic], 1835 is restricted to the
>Indo-Pacific (Seychelles Is.). The distribution of A. sertularium [sic] he
>provides is from "North Carolina to Florida, Texas, W. Indies, Northern
>South America, Brazilian coast, Uruguay to Tierra del Fuego."
>
>However, Gary Rosenberg (www.malacolog.org) considers Costoanachis floridana
>as a valid species, and C. sertulariarum as not occurring in the Gulf of
>Mexico, therefore, we are calling the species that lives in Texas C.
>floridana.
>
>Fabio M.
>
>Rios, E. C. 2009. Compendium of Brazilian Sea Shells. Universidade Federal
>do Rio Grande, and Museu Oceanográfico Prof. Eliézer de Carvalho Rios. Rio
>Grande, RS. 668 pp.
>
>-------------------------------------
>On Wed, Dec 30, 2009 at 5:09 AM, marlo <[log in to unmask]> wrote:
>
>                 Yes we consider them the same.  See Harry Lee's book Marine
>Shells of NE Florida.  He notes that E.C. Rios, 1994. Seashells of Brasil 2a
>edicao.
>                 Fundacao Cidade do Rio Grande, Rio Grande do Sul, Brasil,
>99. 1-368, placed C. floridana. in synonymity to C. sertulariarum,
>considering the Florida and Brasilian shells the same.
>
>                 -----------------
>                 Fabio Wiggers wrote (12/29/09):
>                 Interesting to note that Anachis (or Costoanachis)
>sertulariarum also occur down here in south Brazil. I wonder if they are
>indeed the same species, or they are in fact two or more similar species.
>
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