III.—The genus Bouchardia (Brachiopoda) and the Age of the Younger Beds of Seymour Island, West Antarctic
Shells with the external aspect of Bouchardia have been known for some time from the New Zealand Tertiary (Oamaruian), and were first described by Hutton in 1905 under the names of Bouchardia rhizoida and B. tapirina . The correctness of this generic ascription was doubted by von Ihering, who stated...
| Published in: | Geological Magazine |
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| Main Author: | |
| Format: | Article in Journal/Newspaper |
| Language: | English |
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Cambridge University Press (CUP)
1918
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1017/s0016756800194816 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756800194816 |
| Summary: | Shells with the external aspect of Bouchardia have been known for some time from the New Zealand Tertiary (Oamaruian), and were first described by Hutton in 1905 under the names of Bouchardia rhizoida and B. tapirina . The correctness of this generic ascription was doubted by von Ihering, who stated that the shells lacked the characteristic external form of Bouchardia. In this, however, von Ihering was mistaken, probably owing to the unsatisfactory nature of Hutton's figures, for these species agree externally with Bouchardia in the very characters which he supposes they lack, viz., the very sharp beak ridges, the more or less straight sides, and the presence of a longitudinal cord over the suture of the deltidial plates. The most characteristic external feature of the shell of Bouchardia is that the sharp beak ridges unite in an apex dorsally of the foramen, i.e. the foramen is epithyrid. In Hutton's supposed Bouchardiæ the foramen is permesothyrid, but almost epithyrid. |
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