. Fossil plants : for students of botany and geology . Paleobotany. C/^,(A^f :^i<^J^ xxvrn] FRONDS 13 Cycas. The presence of a strong midrib and the absence of lateral veins are distinguishing features: the lower margin of the lamina is frequently deourrent (fig. 387, A). In O. circinalis the pinnae may reach 40 cm. in length with a fairly uniform breadth of 2 cm. A frond of this species in the British Museum, not quite complete, has a length of 112 cm.: on the lower part of the raohis strong spines replace the leaflets and near the apex of the leaf concrescent pinnae form a continuous lami
. Fossil plants : for students of botany and geology . Paleobotany. C/^,(A^f :^i<^J^ xxvrn] FRONDS 13 Cycas. The presence of a strong midrib and the absence of lateral veins are distinguishing features: the lower margin of the lamina is frequently deourrent (fig. 387, A). In O. circinalis the pinnae may reach 40 cm. in length with a fairly uniform breadth of 2 cm. A frond of this species in the British Museum, not quite complete, has a length of 112 cm.: on the lower part of the raohis strong spines replace the leaflets and near the apex of the leaf concrescent pinnae form a continuous lamina traversed by seven ribs and dissected at the margin into acuminate teeth (fig. 384): some of the pinnae. Fig. 384. Cycas circinalis, abnormal frond. (From a specimen in the British Museum.) are forked as in Cycas Micholitzii'^ (fig. 385). Several years ago I noticed a similar instance of concrescence in a small plant of C. circinalis in the Royal Gardens, Kew (fig. 387,1). In Cycas Micholitzii the pinnae, reaching a length of 20 cm., are repeatedly and deeply forked (fig. 385, A, B; fig. 400): the pinnae of C. Rumphii var. bifida^ are also deeply dissected. Cycas Beddomei has very narrow pinnae (15 cm. x 2 mm.) similar to those of the Wealden 1 Thiselton-Dyer (65) B.; Bot. 2 Thiaeltou-Dyer (02) p. 560. '. 1909, Tab. 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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