Hemiconus cossmanni (Tate, 1897)
Description.
Shell
biconic, spire about one-third the total length ; embryo relatively large
of one and a half smooth whorls, apex obtuse hemispheeric, the tip
somewhat lateral. Spire-whorls five, the first and second concave by the
development of a spiral rounded border at each suture, on the second whorl an
interstitial thread appears contiguous with the anterior band. The third
and fourth whorls are flat, except for three spiral bands, which ornament
it; the two thick marginal bands are rudely crenulated, the medial
smaller one is smooth. Last whorl with antesutural angulation, the sutural
slope with two spiral ridges, the posterior one is the larger; the
anterior surface carries about twelve elevated angulated spiral ridges,
which are somewhat unequal in size and not very regularly disposed, the
larger ones with coarse blunt crenulations ; the whole surface sculptured
with somewhat sigmoid closely-set striae of growth.
Length
9, breadth 4-5 mm.
Eocene, Muddy Creek, Victoria (one example J. Dennant).
Among the few European species referred to this genus by Cossmann, which I
have had under examination, Conus scabriculus Solander, is the one
to which our fossil shows the greatest resemblance. It differs from the
European species by thick spiral ribs, relatively shorter spire and larger
pullus. The species name is in compliment to M. Maurice Cossmann, who has
so ably advanced our knowledge of Australian Tertiary mollusca.
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Hemiconus
cossmanni (1) Pl.
19 – Fig. 11 Eocene Lower beds, Muddy Creek (Australia) |
Bibliografia Consultata
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(1) - Tate, R., 1897. A Second
Supplement to a Census of the Fauna of the Older Tertiary of
Australia. Journal and Proceedings of the Royal Society of New South
Wales, 31
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