. Fossil plants : for students of botany and geology . Paleobotany. 330 TEIGOHrOCABPALES [CH. though relatively more prominent, is comparable with that m Stephanospermum, while the basal chamber recalls that in the seed named by Scott and Maslen THgonocarpus Oliveri^ but subsequently removed by Sahsbury^ from that genus. There is no evidence as to the parent-plant of Polylophospermum, but it may be assumed to have been a Pteridosperm, probably one of the Medulloseae. Codonospernmm'. Brongniart. Our knowledge of this pecuhar genus is derived from Brong- niart's description of the type-species C
. Fossil plants : for students of botany and geology . Paleobotany. 330 TEIGOHrOCABPALES [CH. though relatively more prominent, is comparable with that m Stephanospermum, while the basal chamber recalls that in the seed named by Scott and Maslen THgonocarpus Oliveri^ but subsequently removed by Sahsbury^ from that genus. There is no evidence as to the parent-plant of Polylophospermum, but it may be assumed to have been a Pteridosperm, probably one of the Medulloseae. Codonospernmm'. Brongniart. Our knowledge of this pecuhar genus is derived from Brong- niart's description of the type-species Codonospermum anomalum* (fig. 506, B, C) from St ifitienne and from Eenault's account of C. olivaeforme^ The seeds are globular or elhpsoidal and reach a length of 2 cm.: the testa is differentiated into an outer flesh. Fig. 498. A, B, Codonospermum. A, C. oUvaeforme, longitudinal section showing the seed-proper and the air-chamber, s; pc, poUen-ohamber. B, Diagram- matic sketch of a Godcmospermum, showing the vascular supply, v, and the fibrous arcs, /, in the wall of the lower part of the seed. C, Aetheotesta elliptica, s, sarcotesta with lacunae; v, vascular supply. (After Renault.) and a sclerotesta and has usually eight ribs. The most striking feature is the division of the seed into two regions, an upper portion containing the nucellus and megaspore and a lower portion in the form of an empty chamber that probably served as a float 1 Scott and Maslen (07) PI. xin. fig. 19. " Salisbury (14). ' KiiSuv, a bell. ' Brongniart (74) p. 257, PI. xxm. figs. 9-12; (81) p. 28, PI. C, figs. 9-12. * Renault (93) A. PI. lxxxvu. ; (96) A. p. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Seward, A. C. (Albert Charles), 1863-1941. Cambridge : University Press
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Keywords: ., bookcentury1800, bookdecade1890, bookpublishercambr, bookyear1898
