390 



ANNUAL EEPORT SMITHSONIAN INSTITUTION, 1918. 



Land, is found in the Triassic at a number of scattered localities 

 and is thought to have been a pteridosperm. 



The Cycadophytes, first recognizable in the Carboniferous, fur- 

 nished one of the most prominent Triassic types of vegetation, rep- 

 resented chiefly by a great variety of frond impressions. Some of 



Fig. 34.— Restoration of Clathopteris (after Berry), x 1/2- 



the genera present at that time were Pterophyllum, Ctenis, Ano- 

 mozamites, Ptilozamites, Otozamites, Sphenozamites, and Nilssonia. 

 The majority belonged to the slender branching-stemmed William- 

 sonia order, rather than to the squat forms like those of the Creta- 

 ceous Cycadeoideas, or the modern cycads. 



