ZAMITES. 81 



more obtusely, and lead us to specimens, such as V. 2227, iu 

 which we have no longer the form characterized by gradually 

 tapered and pointed pinnse. A similar variation in the apices and 

 in the breadth of the pinnse is pointed out by Yokoyama ' in the 

 Japanese examples. The frond figured by Go'ppert as Pt&rophyttum 

 CarnaUicmum 2 shows a certain resemblance to some of the forms 

 of the present species. Heer 3 has compared the present species 

 with Znmia gloluUferm, Heer, from the Korne beds of Greenland. 

 Reference has already been made to Nathorst's substitution of the 

 new genus Zamiophyllum for Miquel's name Dioonites. He points 

 out that the species is from TJrgonian strata, and not of Wealden 

 age as Ettingshausen erroneously states. In referring to the basally 

 narrowed pinnse in the Japanese examples, Nathorst notes that 

 the character is not apparent in the European specimens ; we still 

 find, however, in the examples described from the Rufford Collection 

 abundant proof of this narrowing of the segments. The largest 

 pinna mentioned by this author has a length of 260 mm. and 

 a breadth of 4-6 mm. ; in a pinna which is 3 - 5 mm. broad there 

 are 12 veins, in one with a breadth of 6mm. 17 veins, and 22 

 veins in pinnse 8 mm. broad. Nathorst compares Z. Bucliianm 

 with the recent cycad Zamia media, Jacq. In describing a second 

 Japanese form, which he refers to another species, Z. Naumanni, 

 he expresses the opinion that it may possibly represent the lower 

 part of a frond of Z. Buchianus* it is compared with Zamites 

 Schenku, Schimp. (-=.Z. Gopperti, Schenk), from the Wernsdorf 

 beds. Yokoyama also figures under Nathorst's species Z. Naumanni 

 (pi. xxii. fig. 3, and pi. xxvi.) a portion of a frond with pinnae 

 having a breadth up to 20 mm., but suggests that it may be 

 specifically identical with Z. Buchianm. 



The English examples clearly demonstrate that the pinnse are 

 attached to the surface of the rachis, and not laterally as Nathorst 

 inferred from his less perfect material. Z. Naumanni, Nath., 

 is in all probability identical with Z. Buchianus ; the specimens 

 of the former figured by Nathorst seem in some cases, e.g. pi. iii. 

 and pi. v. fig. 1, to show a surface attachment of the pinnse. 



1 Yokoyama, p. 223. 



2 (1), pi. i. fig. 4. 



3 (A. 3), Fl. foss. Arct. vol. vi. pt. i. p. 12, pi. i. 



4 (A. 3), Deukschr. k. Ak. Wiss. vol. Ivii. p. 47. 



G 



