214 MR R. KIDSTON AND MR D. T. GWYNNE-VATJGHAN ON 



The references to the internal structure of Chelopteris gracilis and Sphallopteris 

 Schlechtendalii, embodied in Eichwald's descriptions of these species, only refer to 

 characters observable by the hand-lens. 



With the object, therefore, of submitting the stems of Chelepteris, Sphallopteris, 

 Anomorrhcea, and Bathypteris to a careful microscopical examination, the Director of 

 the Comite geologique had portions cut from each of these stems, and most generously 

 presented them to us for examination ; and we take this opportunity of expressing our 

 indebtedness and sincere thanks to Mons. Th. Tschernyschew for supplying us with 

 the necessary material for our examination of these genera, and to Mons. Michel 

 Zalessky for the willing labour bestowed on searching for the specimens. To Mons. 

 Zalessky we are further indebted for excellent photographs of the external surface of 

 the specimens, which were taken by Mons. Koch. 



Although in the present paper only Chelepteris gracilis, Eichwald (for which, for 

 reasons stated later, we propose the genus Zalessky a), and a new species of the same 

 genus are described, it is desirable, before proceeding further, to consider the relationship 

 and distinctive characters of Chelepteris, Spliallopteris, Bathypteris, and Anomorrhwa, 

 all of which are placed by Corda # and Eichwald t in the Protopteridese, the chief 

 character of which is the horse- shoe shaped vascular bundle of the petioles. 



Chelepteris, Corda. 



1845. Chelepteris, Corda, Flora d. Vurwelt, p. 76. 



Stem arborescent, round, erect ; exposed cicatrices of leaves supported on elevated 

 cushions, spirally arranged and ornamented with adventitious rootlets. Cicatrices 

 oblong or ovate, with a single median crescent- shaped vascular bundle. 



This genus was founded for the reception of three fern stems which were described 

 by Schimper and Mougeot under the names of Caulopteris Voltzi,\ Caulopteris 

 micropeltis,^ and Caulopteris Lesangeana. \\ 



Eichwald, who adopted this genus for his Chelepteris gracilis, thus describes it: — 



Chelepteris (Corda), Eichwald. 

 1860. Chelepteris, Eichwald, Letheea Rossica, vol. i., p. 98. 



Stem arborescent, straight, cylindrical, formed of petiole bases, very close and 

 cylindrical, disposed vertically in spiral series and showing on their fractured end a 

 single semilunar vascular bundle with rarely occurring adventitious roots in the 

 interstices of the petiole bases ; the ligneous body (stele) is complete and its ivalls 

 are stout. 



* Flora d. Vox well, p. lb. \ Loc. at., p. 92. 



% Monog. d, pluntes foss. du grea biyarre de la chuine des Vosges, p. 65, pi. xxx., pi. xxxi. figs. 1-2, 1844. 



§ Ibid., p. 67, pi. xxxi. fig, :;. || Ibid,, p. 67, pi. xxxii. 





