80 



MISS NELLIE BANCEOFT ON SOME 



necessary or desirable. In this connection, reference may be made especially to the 

 works of Prof. Seward on tlie Jurassic Flora (27, Introd. pp. 1-42; see also 28); of 

 Dr. Wieland, wbose * American Possil Cycads ' includes an account of the geographical 

 distribution of Mesozoic Cycadophyta (37, chap, i.) ; and of Eeistmantel (6, pp. 47, 48), 

 who remarks on the similarity of the Liassic and Inferior Oolite floras to be found along 

 a tract running in a north -westerley directiou from India to England. It is sufficient 

 to note here that the anatomical evidence obtained from the present study of Indian 

 fossils is in accordance with the accepted view of uniformity of the Mesozoic Floras. 



V. SUMMAET. 



1. Certain gymnospermous types of Liassic age from the Eajmahal Hills in Bengal 



described 



2. The cycadophyte remains present amongst the material show the association of 

 stems and fructifications of Williamsonian type with foliage which may be considered 

 as identical with the English fronds Williamsonia pecten. Portions of Dictyozamites 

 falcatus fronds are also present. There are, however, no indications of actual attachment 



of leaves or fructifications with the stems. 



3. The vegetative organs show a combination of recent and fossil cycadean characters. 

 Externally the stems resemble those of recent " armoured " Cycads, the leaf-bases being 

 separated by ramental hairs, instead of the scales usually found in the fossil forms. The 

 single compact woody zone with its narrow medullary rays is a characteristic feature 

 of the fossil stems, differing considerably from the looser structure of recent cycadean 

 wood, formed in certain cases from successive cambiums. The Indian wood, however, 

 shows multiseriately-pitted tracheides like those of recent Cycads, instead of the 

 scalariform type usually occurring in the fossil stems. Like these, the parenchymatous 

 ground-tissue has numerous secretory sacs rather than the gum-canals of the living 

 forms. The " closed " arrangement of the vascular bundles of the leaf-bases and rachises 

 is similar to that seen in the American fossil Cycads, as contrasted with the open or 

 omega type of arrangement in most recent genera. Both types of frond are cycadean 

 in general plan, agreeing with such living forms as some of the Zamias, which show 

 palisade mesophyll, in the possession of which there is also agreement with Cycadeoidea 



ingens. 



4. In the structure of the xylem and medullary rays, and of the leaf -bases with their 

 ramental hairs, there is exact similarity between the Indian stems and the axis of 

 Prof. Seward's Scottish Williamsoma fructification. 



5. The Williamsonian fructification amongst the Indian types seems to agree, so far 

 as evidence is available, in general characters and arrangement of parts with other 

 Williamsonian and Bennettitean forms. 



6. The structural evidence obtained, in conjunction with the external morphology of 

 the specimens, supports the already accepted idea of a uniform Mesozoic Flora. 



