EOCENE EERNS. 



35 



similar form, Asvlenites allosuroides, described by Unger,^ from Eocene beds with Ceri- 

 thiiim margariiaceum. The frond seems tripinnate, the pinnae spreading, and the very 

 small pinnules shortly stipitate, elliptical, and sub-obtuse at both ends. The margin has 

 three to five teeth. The secondary veins quit the midrib at angles of 40° — 50°, are 

 simple, and terminate in the teeth, being therefore of the Craspedopteris vera type. 

 The enlargement (PI. Ill, fig. 1) is after a drawing by Carruthers, who kindly assisted in 

 the elucidation of the specimen, which is very obscure indeed. The pinnules were of 

 great substance, and the leaf has therefore carbonised and broken away. The rachis is 

 zigzag. 



Stur has kindly remarked upon the strong resemblance borne to our species by 

 A. allosuroides. Unfortunately this was also determined upon a specimen in which 

 the details were badly preserved, inasmuch as the carbonised leaf-substance from the 

 same cause has almost entirely dropped out, and only the impression remains. It differs 

 from A. pra- allosuroides in size, it being nearly double, and in the more rotundately 

 elliptical pinnules, and as far as can be seen in their less symmetrical arrangement on the 

 frond. 



It, as well as A. allosuroides, closely resembles Pteris heterojjhi/lla, Linn., which has 

 coriaceous pinnules of exactly the same form, but larger. In this respect the Sotzka 

 species connects the two. The recent Pteris scaberula has the pinnules as finely divided 

 as the Bournemouth form. 



It does not bear any close resemblance to existing species of Pellaa or Asplefiium ; 

 but Gymnogramma leptophjlla slightly resembles it. Its determination is exceedingly 

 doubtful. Heer is of opinion that it is the fertile frond of a species of Tltgrsojyteris^ 

 It may, should better specimens be found, be necessary to unite our species to Unger's ; 

 and this seems the more probable as a great number of Sotzka plants are associated 

 with it at Bournemouth. 



The specimen, which is unique, was found some years ago at Bournemouth, under the 

 Coast-Guard Station, by Mr. W. S. Mitchell and Henry Keeping, and is now in the 

 British Museum. 



(e) Aspidiea. 

 Gen. — Meniphyllum, Ett. 

 Filices herbace(S,fronde pinnata, nervatio BrynaricB composite. 



This genus is allied to Menisciwn in its marginal secondary and short ternary veins, 



1 ' Fossil Flora of Sotzka,' 1. c, p. 25, pi. i, fig. 1. 



2 • Flor. Foss. Arctica,' iv, pi. x ; Jurassic flora of Siberia. 



