igol] White — The Genus Whittleseya. 109 



relatives and Ginkgo leaves g-iven by Saporta, ^ Ward,^ Seward 

 and.Gowan,^ and Zeiller. * The other circumstance, lending- some 

 minor colour of probability as to the relationship, is the occurrence, 

 in especial abundance in the beds containing Whittleseya of numer- 

 ous types of gymnospermic fruits, some of which represent genera 

 closely analogous in structural characters to those of the living 

 "maiden-hair tree," Ginkgo hiloba. In the judgment of the writer the 

 Whittleseyce are the oldest representatives of the Ginkgoales stock 

 that have yet been discovered. The fruits of this type are prob- 

 ably included in some of the American species of Rhahdocarpos, or 

 possibly in Cardiocarpon. The plant from the Upper Coal 

 Measures of Bale de Chaleur described by Dawson'' as Nwggerathia 

 dispar, although fragmentary and very incomplete, appears by its 

 petiolate development, the basi-marginnl nerves, and the banding 

 of the parallel, longitudinal nervation to be also referable to the 

 sam£ stock, if not to the same genus. The Nceggerathia dispar 

 may perhaps, without too great an assumption, be regarded as a 

 connecting link between the earlier Whittleseyas and the later 

 Saportcea of Fontaine and I. C. White, "^ from the Dunkard or 

 supposed Permian of the Appalachian trough. Saporttca'^ through 

 its allied genera, Baiera, and Ginkgophyllum, may perhaps be 

 safely regarded as belonging to the Ginkgo stock, while the two 

 genera last named are not only closely related, but one of them is 

 perhaps antecedent to the genus Ginkgo, which is unquestionably 

 present with characteristic flowers and fruits in the earlier Meso- 

 zoic. During this epoch Ginkgo, which in the world of to-day is 



' Evol. reg. veg-., Phanerog-., vol. I, 1S85, pp. 142-146. 



- Science, vol. X, 1S85, p. 496. 



■* Annals of Botan}-, vol. XI\', 1900, pp. 109-154. 



* Elements de Piileobotanitjue, 1900, pp. 248-253. 



^ Quart. Jour. Geol. Soc. London, vol. XXII. 1866, p. 153, PI. XIII, fig. 

 91. 



** Permian Flora, pp. 99, loi, 102, pi. XXXV'III. tigs. 1-4. 



' Saportcea, F. and W., antedates and is quite distinct from Saportia, a 

 genus of Tertiar\- Algae, named by Squinjibol in 1891, Contr. Fl. Fosb. Terz 

 Liguria, pt. i , p. xx. 



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