Tag Archives: Hirasea

Hirasea katoi Habe

Kato’s Hirasea Snail (Hirasea katoi)

Kato’s Hirasea Snail was described in 1973 based on only two specimens that were collected from dune deposits of probably Pleistocene age on the island of Minamijima, Ogasawara Islands, Japan.

The shells reached sizes of 0,3 cm in height, they were very flat, opercular in shape with an extremely depressed spire and a sharply marginated periphery. [1]

***

The species probably disappeared sometimes at the end of the Pleistocene or the beginning of the Holocene.

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References:

[1] Tadashige Habe: Fossil land snails from Minami-jima, Bonin Islands. Science Reports of the Tohoku University, Special Volume 6 (Hatai Memorial Volume): pages 51-53. 1973

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edited: 11.05.2019

Hirasea eutheca Hirase

Straight Hirasea Snail (Hirasea eutheca)

The Straight Hirasea Snail was described in 1907; it is, or maybe was, restricted to the island of Hahajima in the Ogasawara Islands, Japan.

The shells reach sizes of about 0,2 cm in height and about 0,3 cm in diameter; the spire is low-conic and the base very convex.

The species is now likely extinct. [1]

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References:

[1] Robert H. Cowie; Claire Régnier; Benoît Fontaine; Philippe Bouchet. Measuring the Sixth Extinction: what do mollusks tell us? The Nautilus 131(1): 3-41. 2017

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Depiction from: ‘The Conchological Magazine 1907’

(public domain)

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edited: 17.05.2022

Hirasea insignis Pilsbry & Hirase

Remarkable Hirasea Snail (Hirasea insignis)

This species was described in 1904; it is, or maybe was, restricted to the island of Mukojima in the Ogasawara Islands, Japan.

This is a very small species; the shells reach sizes of about 0,2 cm in height and about 0,3 cm in diameter. “Shell imperforate, depressed, with low-conic spire and convex base, impressed in the center. Brown. Very finely and regularly striate radially above, smooth below. Whorls 5, convex, very slowly widening. Aperture crescentic, narrow, the lip strengthened by a strong white rib within, abruptly stopping short of the upper insertion. A long, erect callous lamina stands at the edge of the parietal callous.” [1]

The species might now be extinct. [2]

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References:

[1] Henry A. Pilsbry; Y. Hirase: Descriptions of new land snails of the Japanese Empire. Proceedings of the Academy of Natural Sciences of Philadelphia 56: 616-638. 1904
[2] Robert H. Cowie; Claire Régnier; Benoît Fontaine; Philippe Bouchet. Measuring the Sixth Extinction: what do mollusks tell us? The Nautilus 131(1): 3-41. 2017

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Depiction from: ‘The Conchological Magazine 1907’

(public domain)

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edited: 17.05.2022

Hirasea profundispira Pilsbry

Deep-coiled Hirasea Snail (Hirasea profundispira)  

The strange-looking Deep-coiled Hirasea Snail was described in 1902.  

The species comes from the island of Chichijima in the Ogasawara island group, Japan and is considered most likely extinct.  

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Depiction from: ‚Henry August Pilsbry: Papers on Mollusca of Japan. Philadelphia 1901-12 ‘  

(not in copyright)  

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edited: 20.03.2018

Hirasea minamijimana Habe

Minamijima Hirasea Snail (Hirasea minamijimana) 

The Minamijima Hirasea Snail was described in 1973 based on five specimens that were collected from probably Pleistocene deposits on the island of Minamijima, Ogasawara Islands, Japan. 

The shells reached sizes of about 0,56 to 0,64 cm in heigth, they were ashy white and their surface was ribbed by distantly placed rough growth lines. [1]

***

I do not know for sure when this species actually disappeared, but I assume it to be a Pleistocene/Holocene border extinction.

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References:

[1] Tadashige Habe: Fossil land snails from Minami-jima, Bonin Islands. Science Reports of the Tohoku University, Special Volume 6 (Hatai Memorial Volume): pages 51-53. 1973

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edited: 11.05.2019

Hirasea planulata Pilsbry & Hirase

Planulate Hirasea Snail (Hirasea planulata) 

The Planulate Hirasea Snail was described in 1903, it is or was endemic to the island of Hahajima in the Ogasawara Islands of Japan.

The shells reach sizes of about 0,18 cm in heigth and about 0,32 cm in diameter, they are yellowish brown, dull and very densely, very finely radially striatea above, becoming smooth and glossy beneath. [1]

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References:

[1] H. A. Pilsbry; Y. Hirase: Notices of new Japanese land shells. The Nautilus 17(4): 44-46. 1903

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Depiction from: ‘The Conchological Magazine 1907’

(public domain)

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edited: 11.05.2019

Hirasea diplomphalus ssp. latispira Pilsbry

Wide-spired Hirasea Snail (Hirasea diplomphalus ssp. latispira) 

The Wide-spired Hirasea Snail was described in 1902, it is or was endemic to the islnd of Chichijima, Ogasawara Islands, Japan.

This form is similar to the nominate race but differs from it that the spire is wider and less sunken. [1]

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References:

[1] Henry A. Pilsbry: New land mollusks of the Japanese Empire. The Nautilus 16(2): 45-47. 1902

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Depiction from: ‘The Conchological Magazine 1907’

(public domain)

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edited: 11.05.2019

Hirasea biconcava Pilsbry

Concave Hirasea Snail (Hirasea biconcava)  

This species was described in 1907, it was restricted to the island of Hahajima in the Ogasawara Islands, Japan.  

The shells reach a height of about 0,2 cm and are about 0,4 cm in diameter.  

***

This species is also treated as subspecies of the Plane Hirasea Snail (Hirasea planulata Pilsbry & Hirase) . 

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Depiction from: ‘The Conchological Magazine 1907’  

(public domain)

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edited: 11.05.2019

Hirasea major Pilsbry

Large Hirasea Snail (Hirasea major)  

This species was described in 1902, it was restricted to the island of Chichijima in the Ogasawara Island group of Japan.  

The shells are quite large for the genus, they reach heights of about 0,33 cm and are up to about 0,67 cm in diameter, they are depressed, lens-shaped, brown, dull and densely striate above, paler and somewhat glossy beneath.  

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References:  

[1] Henry A. Pilsbry: New land mollusks of the Japanese Empire. The Nautilus 16(4): 45-47. 1902  

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Photo from: ‘Y. Hirase: The Conchological Magazine 1(1). 1907’

(public domain) 

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edited: 10.10.2017

Hirasea sinuosa Pilsbry

Sinuose Hirasea Snail (Hirasea sinuosa) 

The Sinuose Hirasea Snail was described in 1902, it is or was endemic to the island of Hahajima, Ogasawara Islands, Japan.

The shells of this species reached sizes of about 0,21 cm in height and about 0,43 cm in diameter [1]

***

Unfortunately it appears to be exremely hard to get any reliable information about this enigmatic snail genus.

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References:

[1] Henry A. Pilsbry: Notices of new Japanese land shells. The Nautilus 15(10): 116-119. 1902

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edited: 11.05.2019

Hirasea hypolia Pilsbry

Hypolia Hirasea Snail (Hirasea hypolia)  

This species was described in 1902, it was restricted to the island of Chichijima in the Ogasawara Islands group, Japan.  

***

It is almost impossible to find out any information about this species and many other invertebrates from Japan.  

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edited: 10.10.2017