120 DlCrYOPHYLLUM. 



accurately express the affinity of the plants referred to these 

 genera if they were regarded as generically identical, but it may be 

 more convenient to retain the genus Clathropteris, as representing 

 a fairly well defined type. 



Presl instituted the genus Camptopteris l for certain ferns named 

 by Brongniart Phlebopteris. The figure given by Presl of his 

 type-specimen, C. Muensteriana a plant subsequently referred 

 to the species Clathropteris platyphylla represents a small piece 

 of frond with the venation characters of Brongniart' s genus 

 Clathropteris. 



Another plant, named by Brongniart Phlebopteris Nilssoni, and 

 included by Presl in his genus Camptopteris, should undoubtedly 

 be referred to Dictyophyttum. "While there are, I believe, no 

 good reasons for retaining Presl's genus as originally applied, 

 it may be convenient to retain it in the modified sense in which 

 Nathorst has applied it to some remarkable specimens of Rhsetie 

 age from Scania. 2 A restoration published by Nathorst of 

 Camptopteris spiralis, Nath., in his Geology of Sweden? admirably 

 illustrates the habit of the genus. Having had an opportunity 

 of examining the Scanian fossils in the Stockholm Museum, I can 

 bear testimony to the accuracy of Nathorst's restoration. It is 

 probable that a specimen recently figured by Zeiller* as the 

 base of a Clathropteris frond should be referred to the genus 

 Camptopteris as used by Nathorst. 5 



Bunker's genus Hausmannia was instituted in 1846 6 for an 

 imperfect leaf from the North German "Wealden. The type- 

 specimen, H. dichotoma, has a palmate frond, deeply divided into 

 lobed linear segments traversed by forked main veins from which 

 anastomosing branchlets are given off. The type-specimen of 



1 Sternberg (38), p. 168, pi. xxxiii. fig. 9. 



a Nathorst (78 2 ). 



8 Nathorst (94), p. 169. 



* Zeiller (97), pi. xxi. fig. 6. 



6 Since this was written, M. Zeiller, of Paris, has published an excellent work 

 on Palaeobotany (Elements de Paleobotanique), in which he figures an unusually 

 perfect specimen of Clathropteris platyphylla, Gopp., from Tonquin ; this is 

 by far the finest example so far described of a Mesozoic species which presents 

 a striking resemblance to some forms of the recent genus Dipteris, and in habit 

 agrees also with JUatonia pectinata and Cheiropteris palmatopedata (Bak.). 



6 Dunker (46), p. 12, pi. v. fig. 1. 



