. Fossil plants : for students of botany and geology . Paleobotany. 438 BENNBTTITALES [CH. (fig. 552). The microspores, 58—65/i in length, are rather narrow, ovate and very similar to those described by Solms-Laubach^ in Cycadeoidea etrusca. The synangia are attached in two rows to slender lateral segments which appear to be given off from the upper face near the median line of the broad linear sporophylls (fig. 565, A). Nathorst points out that the position of the fertile pinnae brings the sporophylls into close relation with the vegeta- tive fronds of Ptikyphyllum pecten and other Cycadean f
. Fossil plants : for students of botany and geology . Paleobotany. 438 BENNBTTITALES [CH. (fig. 552). The microspores, 58—65/i in length, are rather narrow, ovate and very similar to those described by Solms-Laubach^ in Cycadeoidea etrusca. The synangia are attached in two rows to slender lateral segments which appear to be given off from the upper face near the median line of the broad linear sporophylls (fig. 565, A). Nathorst points out that the position of the fertile pinnae brings the sporophylls into close relation with the vegeta- tive fronds of Ptikyphyllum pecten and other Cycadean fronds in which the pinnae are attached to the upper face of the Fig. 552. WilUamsonia spectahilis. Restoration of an almost mature male flower. (After Thomas; approximately nat. size.) While the longer pinnae in the middle portion of a sporophyll bear several synangia, those near the base and apex are shorter and, in the proximal region nearer the broad cup formed by the coherent bases of the sporophylls, occur singly, thus approaching the condition characteristic of W. whitbiensis (fig. 565, B) in which they are sessile on the simple microsporophylls. It is noteworthy that in some specimens figured by Nathorst there is a tendency 1 CapeUini and Solms-Laubach (92) PI. v. fig. 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
