. Bulletin of the Natural Histort Museum. Geology series. 126 C. BUTTLER. Figs 16-18 Batostoma clogyfranense sp. nov. 16, NHM PD 8362 (holotype), longitudinal section, x22. 17, NHM PD 8374 (paratype), longitudinal section, x30. 18, NHM PD 8362 (holotype); 18a, transverse section, x30: 18b, tangential section, showing infilled zooecia, x37; 18c, tangential section, x86. Fig. 19 Batostoma cf. polare Aitrowa 1965. NHM PD 8324; 19a, longitudinal section, x22; 19b. longitudinal section, x70; 19c, tangential section, x41; 19d, tangential section, x96. exozone, and mesozooecia are less common in the
. Bulletin of the Natural Histort Museum. Geology series. 126 C. BUTTLER. Figs 16-18 Batostoma clogyfranense sp. nov. 16, NHM PD 8362 (holotype), longitudinal section, x22. 17, NHM PD 8374 (paratype), longitudinal section, x30. 18, NHM PD 8362 (holotype); 18a, transverse section, x30: 18b, tangential section, showing infilled zooecia, x37; 18c, tangential section, x86. Fig. 19 Batostoma cf. polare Aitrowa 1965. NHM PD 8324; 19a, longitudinal section, x22; 19b. longitudinal section, x70; 19c, tangential section, x41; 19d, tangential section, x96. exozone, and mesozooecia are less common in the Russian species. Two species of Batostoma have been previously described from the Lower Palaeozoic of the Welsh Basin. B. murchisotu was de- scribed by Spjeldnaes (1957) from 'Horderley' in Shropshire. This species has few diaphragms and mesozooecia, and acanthostyles are absent, suggesting that the species may not belong to Batostoma. A re-examination of the type material is required. Owen (1962) described Batostoma sp, from the Aymestry Limestone (Ludlow Series, Silurian), Wenlock. This species has a very small exozone and mesozooecia are absent. Batostoma cf. polare Astrova, 1965 Material. NHM PD 8324. Fig. 19 Description. Zoarium erect with narrow cylindrical branches, on average mm in diameter. Autozooecia are parallel to the branch axis within the endozone and curve abruptly outwards in the exozone to meet the zoarial surface at 90°. The autozooecia within the endozone have thin, slightly wavy walls. The exozone is thick with an average diameter of mm. It is recognised by an extensive thickening of the zooecial walls and a simultaneous change in zooecial orientation. Autozooecia all origi- nate in the endozone, where they are polygonal-rounded in transverse section. They become circular in the exozone, as seen in tangential sections of branches. Autozooecial diameters average mm by mm within the exozone. Diaphragms are present throughout the autozooecia,
Size: 1810px × 1381px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bhlconsortium, bookc, bookcentury1900, bookcollectionbiodiversity
