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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