FLORA OF rilF SHASTA FOUMATION. 249 



(lilTci'ciit snl)fi«'iici-:i. Scwnrd's plants -aw evidently a (|uit(' (li(Tci-(Mit 

 t\|)c fi-oni thoso. Natlioi-st's ZdiiiiojihijUinn Xuunidnni, found in the 

 same Japanese foi-niation as the specimens of Dioonites Burl/KUins, 

 which he names /(niiioplii/llNin Budiianuni, is a spcries of the same type 

 as Seward's foi'ins. It is pi'oliahly spcH'ilically dilTerent from the latter. 

 Xathoi'st's Zittniopln/Uinii BuchidHion and the original I'lcroplniUuiii 

 Buchinniun of i'^tliniishausen are. in m\- ()j)inion, the same species as tlie 

 Potomac plant. l''or these 1 prefer to retain the name Diooiillcx Buclii- 

 (uius. That name is established, and the genus is as near Dion as Zaniia. 

 Perhaps it would l)e well to make a new genus for the plants with leaflets 

 inserted on the upper face of the midi-il), like those of Seward, in order 

 not further to extend the application of Zamites. This new genus 

 might l)e called Zamiophyllum, as Xathorst proposed. 



1 think that some of the confusion that has arisen in the classifi- 

 cation of cycads, based partly on the mode of insertion of the k^iflets, 

 comes from the fact that authorities have Tiot used the desci'iptions 

 "attached to the upper face of the midrib" and "attached o)i the upper 

 face" always in the same sen.se. It may be meant, in the case of the 

 formei', that the leaflets are attached, not on the uplK'i' face and within 

 its margin, as in the case of Seward's plants, but to the sides of it, so as 

 to l)e in the same plane with the upper face of the midril), as is ti'ue of 

 Dioottiles Buchianus. Certainly it is very desirable that there should be 

 a thorough revision of the classification of the fossil cycads that are 

 known only \)\ their leaves. In Monograph XV of the United States 

 Geological Survey, page 181, speaking of Bornemann's genus Dioonites," 

 as characterized by Schimper, I made the latter say that the leaflets 

 are "sometimes expanded at.base so as to extend up and down the I'achis." 

 This was a translation of Schimper's words "basique leniter pro- et 

 decurrentibus," which he used in his synopsis of the character of Dioonites, 

 given on page 128, Vol. 11, of his Traite. It escaped my notice that on 

 page 147 of the same volume, in giving again the character of this genus, 

 he uses different words, viz, "e basi anguste decurrente, hand angustata." '' 



« Tlic genus Dioonites was named and described by Miqucl in 18.51 (Over de Kang.schililcing dcr fossiele 

 ("vcadca': 'Iljdschr. v. d. Wis-on Naturli. Wetensch., Deel IV, .\mstcrdam, 18.51, p. 211 ["]), and is so 

 cri'dited l)y BomciiiaiiM. Mi(|iicl did not refer Ettingsliausen's Ptcrophjllum Buchianum t«) this geiuis. It 

 was named from its rcsenililniicc to Liiidley's living genus Dion, wrongly spelled Ilioon by many authors. — 



L. F. W. 



'' Miijuel's langmige for Ibis cbaracter is as follows: •'irifiMiic rclrorsum subdecurrcntiH." - L. !■'. \\ . 



