Tag Archives: La Gomera

Hemicycla montefortiana Beck & Rähle

Monteforte Land Snail (Hemicycla montefortiana)

This species was described in 2006, its (sub)fossil shells were found in fossil beds in the Barranco de Monforte on the island of La Gomera, Canary Islands.

The shells reach sizes of about 4,6 cm in diameter, they are very similar to those of another extinct member of this genus, Mousson’s Land Snail (Hemicycla moussoniana (Wollaston)) but are larger. [1]

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The fossil beds of La Gomera have been dated to Late Pleistocene to Holocene age, thus the Monteforte Land Snail may very well have survived into the Holocene.

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References:

[1] T. Beck; W. Rähle: Description of a newly discovered extinct repreentative of the genus Hemicycla Swainson, 1840 (Gastropoda, Pulmonata, Helicidae) from La Gomera, Canary Islands. Basteria 70: 53-56. 2006

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edited: 05.12.2018

Hemicycla gomerensis (Morelet)

La Gomera Land Snail (Hemicycla gomerensis)

This species was described in 1864, it is or was endemic the the island of La Gomera, Canary Islands.

The shell reaches a size of about 2,1 cm in diameter.

In proportion to its size the shell is extremely thin and fragile, being more than usually sub-diaphanous when held up to the light; and its colour is a deep castaneous-brwon, but rather paler (or more olivaceous) beneath, with extremely indistinct indications of three obsolete darker bands, – one of which is just below the dorsal line, another immediately above it, and the third a little behind the suture (the space between this last one and the suture being sometimes, apparently, though not in the specimens now before me, of a more lively ochreous yellow).” [1]

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The La Gomera Snail is listed in the Red List of the IUCN as ‘data deficient’, but may be already extinct.

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References:

[1] T. Vernon Wollaston: Testacea Atlantica: or the Land and Freshwater Shells of the Azores, Madeiras, Salvages, Canaries, Cape Verdes, and Saint Helena. London: L. Reeve & Co. 1878

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Depiction from: ‘George W. Tryon; Henry A. Pilsbry; a.o.: Manual of Conchology. Second Series: Pulmonata Vol. 4, Helicidae Vol. 2. 1888’

(public domain)

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edited: 05.12.2018