CATALOGUE OF MESOZOIC PLANTS 279 



Cretaceous times are very scanty and not yet properly investigated, 

 we find that some of the Cretaceous beds, especially in Portugal, 

 North xVmerica, Greenland and Moravia, are full of dicotyledonous 

 leaf-impressions, many of them resembling leaves of modern 

 genera. It is thus of the greatest importance that the Cretaceous 

 flora should be critically examined and catalogued. The British 

 Museum, too, possesses at South Kensington vast stores of 

 beautiful fossil plants of Cretaceous and Tertiary Ages, which 

 have never been properly studied and described, and it is very 

 satisfactory that a commencement of this work has been made. 

 The difficulties of the task are appalling, and the author of the 

 present work found that no progress could be made until a list of 

 the material had been compiled. This list occupies a large part 

 of the volume. The references to papers on Cretaceous plants 

 published before 1910 occupy forty-seven pages, and the list of 

 species described extends to another hundred and eighty-seven 

 closely printed pages. 



The more descriptive part of tlie book deals with the Alga? and 

 Fungi. The families Codiace®, Dasyscladacete and Corallinacese 

 are represented by forms which were fairly well preserved by 

 their calcareous incrustation, and show clearly their vegetative 

 structure, though naturally their reproductive organs are scarcely 

 ever preserved. The genus Lithothamnium appears to be repre- 

 sented by a number of species whose external form and internal 

 structure certainly resemble that of the recent genus, though the 

 absence of reproductive structures renders the use of this generic 

 name a little speculative. The much-discussed forms called 

 Chondrites are doubtfully placed in the order Phgeophycese. 

 Much controversy has arisen as to whether the impressions of 

 this type are really to be regarded as plant remains or merely as 

 artifacts mechanically produced. The author has come to the 

 conclusion "that the genus 'Chondrites' does contain ' species ' 

 which are truly the remains of Algae, though many of those de- 

 scribed for the genus are probably of purely physical phenomena," 

 and that in any case it is useful to retain this genus for the 

 present. 



The Cretaceous fungi are not of special interest, because their 

 remains are so scanty, though petrified wood, &c., sometimes 

 contains well-preserved examples of parasitic forms. The form 

 called Pleosporites Shiraimis seems to be a w^ell-marked Pyreno- 

 mycete infecting the leaves of Cryptomeriopsis, and some other 

 imperfectly known forms are placed among the Pyrenomycetes. 

 Some leaf impressions have the appearance of infection with a 

 fungus of the Bhytisma type, but a great deal of uncertainty 

 attaches to these specimens. One or two forms infecting wood 

 have been referred to the Basidiomycetes, but their identification 

 with this group is somewhat speculative. We shall await the 

 appearance of the second volume of this work with much interest, 

 hoping that the author will make clear how much reliance we are 

 to place on the identification of Cretaceous dicotyledons with 

 modern genera. H H T 



