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Shell bracelet
Recently Cernohorsky (1964, Sean Raynon Sabado, NS #54:6) has figured similar abnormalities from Mauritius, but they also
occur in Queensland: Iredale (1939, Austr. Zoologist 9:319, pl. 29, fig. 24-26) figured rostrate melanistic Melicerona
listeri Gray (called by him M. melvilli velesia Iredale) from the Capricorn Islands, and I possess similar shells from Wilson
Island off Gladstone (leg. A. Nash 1954).
Besides, Mr. Cedric Coucom told me by letter that Pumpkin Island, (about one mile south of North Keppel Island and about 8.5
miles E.N.E. of Yeppoon) yielded wonderful specimens of melanistic cowries.
He described this "shell collector's paradise" as follows: "The island comprises two elevated pieces of land divided by a
narrow channel which goes dry at low tide. Coral is present here and sea weed is plentiful." The Keppel Islands lie within
"the area covered by fresh water when the Fitzroy river is in flood," which fact may affect the cowries. In May, 1964, Mr.
Coucom collected some more rostrate, melanistic Erronea errones Linnaeus and Purpuradusta gracilis macula Angas at the same
place, and presented them to the writer; one extremely rostrate shell of each species has been figured above: fig. 1 - 3
represents the base, dorsum, and columellar margin of errones (coll. Schilder 17856: length 25.6 mm), fig. 4 - 6 represents
the same views of macula (coll. Schilder 17862: length 20.8 mm).
The cause of rostration is still doubtful: explanations range from hurts of the mantle (Sullioti 1924) to living in muddy
bottom (Schilder 1927, 1938) or on sea fans (Tomlin by letter about in 1930), and influence of metals (Cernohorsky 1962);
surely it should be regarded as modification, and not as hereditary. Any solution of the problem must consider the following
five facts:
Although Mighels rightfully bemoaned the fact that his collection could never be replaced after the disastrous fire of 1854,
it has been possible to select neo-holotypes (a specimen selected as the type subsequent to the original description in cases
where the primary types are definitely known to be destroyed) or lectotypes (specimens which are, subsequent to the
publication of the original description, selected and designated through publication to serve as "the type") for many of
Mighels' species. Mighels had fortunately sent types of some of his species to the Boston Society of Natural History, C. B.
Adams, and J. G. Anthony, and all of those are now in the Museum C. walkeri bregeriana has been established as a species by
Crosse in 1868 (Diagnoses molluscorum, Jour. de Conch., Vol. 16:277, Paris). It had been treated as a full species by
Roberts, 1870, Weinkauff, 1881, Rossiter, 1882, Paetel, 1887, Smith, 1888, Campbell, 1889, Kenyon, 1902, and Schilder, 1924.
bregeriana was regarded as a variety or subspecies of walkeri by Sowerby, 1870, Roberts, 1885, Hidalgo, 1906/7 and Schilder
in all publications after 1924.
The holotype of C. w. bregeriana came from New Caledonia, and a variation of bregeriana from this Island was described as
rossiteri by Dautzenberg in 1906. All the known specimens came from New Caledonia, with the exception of three, which were
collected at Joanet Island, Louisiade Archipelago, East of New Guinea (E. A. Smith, "Note sur le C. bregeriana, Crosse,"
Jour.de Conch. Vol. 36:313, Paris 1888).
C. w. bregeriana agrees fairly well in size, width, number of labial and columellar teeth with other races of walkeri.
However, it can be easily separated from these on account of the small and numerous (60-100) distinct white spots on base and
margins. It appears that C. w. bregeriana is what Schilder terms a "semi-species," which is a species in statu nascendi,
similar to C. onyx adusta, C. subviridis dorsalis, C. lutea humphreysii, etc. C. w. bregeriana can easily be separated from
all the known species and subspecies of Cypraea, much easier in fact than many of the allied but separate species of Cypraea
like luchuana-pallidula-interrupta-summersi or arabica-eglantina-grayana-histrio, etc. Sketch [after] F.A. Schilder
Sketch: Radula of Cypraea w. bregeriana
Description of C. bregeriana (the shell): Pyriform in shape, fairly light in weight with the right side calloused. The
greyish to fawn dorsum is speckled with numerous, small, olive-green spots and is crossed by a fairly wide, brown transverse
band. This band may be saturate or pale, continuous or interrupted. In the latter case the edges of the transverse dorsal
band are arranged in the form of rectangles. The dorsal line is usually absent. However, 3 specimens examined showed a
distinct dorsal line connecting both extremities (Ill. shell figs.1 and 2). The anterior extremity is flanked by 2
purplish-brown spots, and the dark brown spiral blotch in the umbilicus is pronounced. A lilac rim encircles the dorsum near
the margins, and this rim is either continuous or interrupted, distinct or pale lilac. The marginal spots, which are dark
brown in colour, number about 5 - 13 on the labial side and 6-10 on the columellar side. (These marginal spots are absent on
Fiji specimens). The aperture is somewhat dilated anteriorly, labial teeth cross over half the base and columellar ones one
quarter to one half the base. The first columellar tooth (especially in Fiji specimens) is extremely nodulose, and teeth
interstices are extremely dull and tinged with purple. The colour of the base varies from rich brown to ferrugineous, and the
whole base is spotted with small, pure white spots, which extend up to the margins. These spots number 60 - 100 and vary in
diameter from 1/4mm to 1/2mm, and are most conspicuous and visible even in badly beach-washed shells.
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