396 



ANNUAL REPORT SMITHSONIAN INSTITUTION, 1918. 



nites, Stenopteris, Ctenopsis, Zamiopsis, Nilssonia, Dichotozamites. 

 Podozamites, Glossozamites, Anomozamites, Cycadites, Otozamites, 

 Zamites, and Pterophyllum. 



In addition the squat forms so common in a petrified condition at 

 this time and represented by the genera Cycadeoidea and Cycadella, 

 (the former of which has furnished so much information regarding the 

 structure and morphology of the fructifications) are to be mentioned 

 as important elements in the flora as well as the detached bract-en- 

 circled fructifications of the slender stemmed or Williamsonia forms. 

 The Ginkgoales were represented by several species of Ginkgo and by 

 numerous occurrences of Baiera, although neither genus is as common 

 as it was earlier. The Taxaceae seems to have been more prominent 



than later, with species of 

 Nageiopsis and Cephalo- 

 taxopsis, both of which 

 were individually abun- 

 dant. The Araucarian 

 conifers are well repre- 

 sented, but in no great va- 

 riety. The Abietinaceae 

 showed numerous forms of 

 Abietites and before the end 

 of the Lower Cretaceous, 

 undoubted species of Pinus 

 are known, and Cedrus has 

 also been recorded. 



Sequoia, Sphenolepis, and 

 Arthrotaxopsis represented 

 the Taxodiaceae, while Fre- 

 nelopsis and Widdrington- 

 ites, which were widespread, 

 represented the Cupres- 

 saceae. Brachyphyllum and 

 Czekanowskia continued to survive. Little can be said about the 

 Lower Cretaceous flowering plants. Certain genera from the oldest 

 Potomac (Rogersia, Ficophyllum, Proteaephyllum) have been de- 

 scribed as angiosperms, but they more likely represent Gnetalian forms 

 comparable with the modern Gnetum. The are poorly preserved im- 

 pressions and might even represent fragments of the fronds of Dip- 

 teriaceous ferns — a conclusion amply proved for one of Saporta's 

 proangiosperms (Protorhipis). This author has described a num- 

 ber of indefinite plant fragments from Portugal as Poacites, Rhizo- 

 caulon, etc., some of which he calls proangiosperms, while similar 

 fragments are called monocotyledons. They are all entirely incon- 

 clusive. Nothing remotely suggestive of flowering plants is known 



Fig. 36.— Restoration of a fertile frond of Schizaeopsis from 

 the Lower Cretaceous (after Berry), x 4/5. 



