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The following names should be treated as synonyms: amabilis Jousseaume 1881 = walkeri; merista Iredale 1939 = continens;
barbara Kenyon 1902 and rossiteri Dautzenberg 1903 = bregeriana. The juvenile Ipserronea problematica Iredale 1935 surely
does not belong to walkeri (as Allan 1956, Cowry Shells p. 49 suggested), but to Erronea pyriformis Gray 1824 (see Iredale
1939, Austr. Zoologist 9:317).
In these years after World War II, many interesting cowries have been collected, and much new information became known to us,
also concerning walkeri, so that we were obliged to revise our views, both with regard to taxonomy and distribution.
Taxonomy: The East Australian continens cannot be separated from the Malayan surabajensis; but there seems also to be no
constant character of the Lemurian walkeri, though the latter seems to be generally smaller, paler, and less zonate than the
Malayan "race'' (which should be called continens by law of priority). Whereas the Philippine shells from Siassi Is. are
usually very large (30 to 35 mm.) and dark (dorsal zone vividly brown, well marked, aperture purple throughout), a population
from Ubey on Bohol Is. (destroyed in the museum of Hamburg, one shell No. 3120 in my collection excepted) recalls the
Lemurian shells in size (17 to 25 mm.) and color (creme, zones obsolete, interstices of columellar teeth only pale purplish).
Therefore all specimens from Lemuria to the Philippines and Queensland should be called walkeri. However, the New Caledonian
race bregeriana has proved to be of almost specific rank, and is characterized by tiny opaque white specks embedded into the
glossy orange base and margins, like no other cowry species, Chelycypraea testudinaria Linnaeus excepted: these white specks
are never absent in well preserved bregeriana (though overlooked by its author!), and generally are recognizable in beach
shells too; but they have never been observed in any walkeri coming from farther west than New Caledonia (Joanett Is.
excepted, see below).
Distribution: The areas from which walkeri has been known to the writer till 1941 have been marked by black circles (walkeri)
and triangles (bregeriana) in the map: The three races of walkeri mentioned above seem to be separated by zones uninhabited
by the species. However, after World War II many new localities became known to us which fill up these gaps, or extend the
limits in northern, eastern, and southern direction. Therefore the following areas should be added, which have been marked,
on the map, by empty circles and triangles respectively:
Figured above is the holotype of Gisortia
gisortiana pterophora Schilder, 1927,
from the Middle Eocene of northern France;
length 260 mm. (over 10 inches).
The largest living cowry is Macrocypraea cervus LINNAEUS from Florida, which according to PRESBREY (1913) grows up to 7
inches (i.e. 178 mm.); however, the largest specimen measured by the writer in forty years investigations is "only" 157 mm.
long (British Museum). The second rank is occupied by Cypraea tigris LINNAEUS, the Philippines race of which, named
schilderiana CATE, attains in deep water 147 mm. (KAY 1961). The third rank must be attributed to Chelycypraea testudinaria
LINNAEUS: the largest specimen of its western race ingens SCHILDER & SCHILDER, preserved in coll. DAUTZENBERG, is not 142 mm.
long (as indicated by SCHILDER 1929), but only 140 mm. (SCHILDER & SCHILDER 1952). It may be observed, that these three giant
species among living Cypraeidae belong to the subfamily Cypraeinae, while the largest Nariinae and Cypraeovulinae are
distinctly smaller.
Some fossil cowries, however, attained even larger dimensions, in fact more than double the length of the largest living
species named above! There is a subfamily Gisortiinae which tends to gigantism, as well as to a reduction in the
denticulation of the lips. They descended from the subfamily Cypraeorbinae which flourished from Cretaceous times to Eocene,
and of which very few species have survived as relics to recent times. The Gisortiinae evidently originated in India in the
Paleocene (about 65 million years ago), flourished during the Lower and Middle Eocene near the Eocene equator from West
America to Europe and India and as far as Taiwan. Then suddenly they became extinct, with the few exceptions, which survived
up to the upper Eocene (about 40 million years ago). No species has been detected in Oligocene beds. During these 25 million
years a general increase in size can be observed, in a hyperbolic way, i.e. the enlargement became gradually faster and
faster -- till the size exceeded the natural limits of existence, and the Gisortiinae became extinct. But let us hope that
one day a living relic of this subfamily may be found in deep water, which has yielded, in these last decennaries, so many
surprising discoveries.
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