. Bulletin of the British Museum (Natural History), Geology. . PLATE 19 Trochiliscus podoUcus , L. Devonian. Figs. 17-19. Page 197. Fig. 17. Portion of an oospore membrane, dissolved out of a gyro- gonite, with a decoration of small irregular granules, x 500. () Fig. 18. Portion of the oospore membrane of another specimen with a similar, but imusually coarse, decoration, x 500. (\'.28345.) Fig. 19. Oospore membrane, dissolved out of a gyrogonite, with more or less circular thickenings, some of which have a minute central pore. X500. () Cham vulgaris L. Recent. Fig. 20. Pag
. Bulletin of the British Museum (Natural History), Geology. . PLATE 19 Trochiliscus podoUcus , L. Devonian. Figs. 17-19. Page 197. Fig. 17. Portion of an oospore membrane, dissolved out of a gyro- gonite, with a decoration of small irregular granules, x 500. () Fig. 18. Portion of the oospore membrane of another specimen with a similar, but imusually coarse, decoration, x 500. (\'.28345.) Fig. 19. Oospore membrane, dissolved out of a gyrogonite, with more or less circular thickenings, some of which have a minute central pore. X500. () Cham vulgaris L. Recent. Fig. 20. Page 213. Fig. 20. Portion of an oospore membrane, for comparison with Figs. 17, 18, 24. The decoration is semi-reticulate, the rounded granules being non-contiguous and of variable size. The dark parallel lines are short lengths of the spiral ridges, x 500. (G. O. Allen Colin.) Cliara cscJieri Unger. Oligo-Miocene. Figs. 21-28. Page 212. Fig. 21. The upper portion of a longitudinal section through a gyrogonite showing the outer oospore membrane and the thin inner membrane, which has contracted away from it. x 58. (\\28559.) Fig. 22. G3-rogonite in longitudinal section. The thick lime-shell, basal opening, and black oospore membrane with prominent flanges between the lime spirals are clearly shown. X58. () Fig. 23. The lower portion of a gyrogonite in longitudinal section. The basal opening of the lime-shell is lined by a membrane forming a cage at the base of the oospore; the cage is divided by a transverse wall (cf. Text-fig. 7a). Portions of other gyrogonites show the well-developed flanges on the oospore membrane, x 86. () Fig. 24. Oospore membrane with a semi-tuberculate decoration, the rounded granules being non-contiguous and of variable size. The spiral ridges to which the ilanges are attached are strongly marked, x 485. () Fig. 25. Portion of oospore membrane with three sub-circular borings. The inner, more translucent, membrane is seen on the edge
Size: 1528px × 1636px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorbritishmuseumnaturalhistory, bookcentury1900, bookcoll
