Category: Shell of the Month

Lyncina ventriculus Lamarck, 1810
On coral reef at night, 15-20 meters
Rasa Island, Palawan, Philippines, 2012

Lyncina ventriculus Lamarck, 1810, is a very heavy massive shell, easily identified by its four dorsal bands that are almost obscured be a thick callous that reaches to the top of the shell. Although Lyncina ventriculus is placed in a large group of cowries, it stands alone with no close relative. When the scientists subdivided Lyncina, they isolated Lyncina ventriculus by itself. Lyncina schilderorum and Lyncina carneola are similar but quite different.
Although not rare, Lyncina ventriculus is difficult to obtain. Whereas most cypraea are collected by the dozens, ventriculus seems to be found one at a time. It’s distribution supposedly ranges from the Philippines thru Polynesia, however only occasional specimens from Tahiti and the Visayas in the Philippines reach the market. Polynesian specimens are much smaller in size than their Philippine relatives.
Our specimen is a giant, almost 60mm in length. It has glossed over growth stress lines on the dorsum which is typical for ventriculus; true gems are a rarity. Otherwise it is a beautiful specimen. Ventriculus fades rapidly after collection. Fresh specimens are vibrant with the upper reaches of the callus black but this rapidly fades to grey. Even storage in darkness will not prevent the fading.
Donated by Richard Kent

Umbilia hesitata Iredale, 1916
Trawled off Cape Howe @ 300-400′
New South Wales, Australia

Our shell of the month was originally described as Cypraea umbilicata Sowerby, G.B.I., 1825, the Umbilicate Cowry. Unfortunately Sowerby hadn’t done his homework and the name was ruled invalid. Finally in 1919, close to a century later, naturalist Tom Iredale named it hesitata, the Undecided Cowry because it was so late in getting a proper name.

The genus Umbilia is a small genus consisting of the southernmost cowries that inhabit the cold deep water off the south coast of Australia. The living species are Umbilia capricornica Lorenz, 1989; Umbilia armeniaca Vercoi, 1912 and our shell Umbilia hesitata Iredale, 1916. Umbilia hesitata has two sub species, an albino form named Umbilia hesitata hesitata howelli (f). Iredale 1931, and a dwarf form Umbilia hesitata beddomei Schilder, 1930. (Umbilia is also known for fossils of several spectacular extinct species.)

Umbilia hesitiata is called the Wonder Cowry. It’s a large shell of 70-100mm with rostrate terminals and a sharp bend to the posterior. The surface is unlike that of any other Cypraea due to minute granulations that give the shell a waxy appearance. The vast majority of hesitata look very similar to this one, white with a light brown mottled pattern. Darker specimens are scarce and very dark colored ones bring a substantial premium that could more than double the price.

This shell was very rare until fishing fleets trawling the depths off New South Wales and the southern Australian coast began netting specimens. It is interesting that the prices on close relative Umbilia armeniaca have dropped dramatically due to increased fishing whereas it’s prices have crept upwards to the point where the two are now close in value. Several years back one could purchase nice specimens of hesitata for about $20-$25, not anymore. Today there is an extreme range in price running from about $30 on the low end to over $100 for exceptional specimens. One reason for the variation in price is that few specimens grade gem as hesitata often suffers flaws. On this specimen the terminals are intact and there are no sand inclusions nor dull areas, however it does have a well healed growth line on the dorsum making it grade as F++.
Donated by Richard Kent

Cypraea vitellus (Linne 1758)

Conus violaceus Gmelin, 1791
Conus nussatella Linnaeus, 1758
Cypraea marginalis Dillwyn, 1817
Cypraea turdus Lamarck, 1810
Oliva bulbosa Röding, 1798

The Horn of Africa juts out from the continent where the Indian Ocean meets the Gulf of Aden. It is a strategic location as shipping from the Suez Canal passes through the Red Sea and the Gulf of Aden on its way to the open seas of the Indian Ocean. Four countries, Djibouti, Eritrea, Ethiopia, Somalia share the peninsula. Somalia is the former Italian Somaliland and British Somaliland. Since gaining independence in 1960 the country has been in near constant turmoil going from extremes as a socialist Soviet satellite and an Islamist nation. Several years back Somalia gained infamy as a heaven for pirates attacking shipping.

The coastal waters are rich in sea life. It is a great location for shells. A few Italian dealers monopolized the trade up until around 2010 when the pipeline dried up. I was fortunate to purchase a large amount shells from a dealer in Rome, both in retail and dealer lots. The shells presented here are from that source. These specimens have decent location data but not habitat as they were “netted by native fishing boats.” All were collected off the southern coast near the port of Merca (also spelled Marka).

Several of the shells warrant further mention. Conus violaceus is an Indian Ocean shell. It is scarce in all locations. Most specimens on the market come from Mozambique. All specimens have some spire erosion so this one is about as nice as they get.

The center of population for Cypraea marginalis is along the Indian Ocean coast of Somalia. It has been widely collected due to its attractiveness and variable pattern. Fresh specimens have an intense purple base which unfortunately fades rapidly. Even storage in darkness will not prevent fading. This is a choice specimen of good size.

Oliva bulbosa is widespread throughout the Indo-Pacific region and comes in more color forms than one could count. Most color varieties have their own individual names. These from Somalia, which came from a wholesale lot, all had a similar color, size and pattern which appears to be unique to the location.

As it is highly unlikely that in 2014 one would find fresh specimens offered from Somalia, winning this raffle makes for an exceptional addition to one’s collection.

– Richard Kent

Cypraea guttata azumai, Schilder 1960

Cypraea guttata, Gmelin 1791 is one of the most exquisite of all shells. Until recently it was also one of the rarest. When Burgess wrote his monumental book “The Living Cowries” in 1970, he stated that there were fewer than 20 known specimens. Today due to the Asian commercial fishing fleets trawling in deep water, specimens consistently come to the market. Cypraea guttata has an orange dorsum with white “drops”; The extremities are rostrate and spiny. The prominent teeth extend the width of the base and are deep brown stained contrasting to a white base.