CATALOGUE OF MESOZOIC PLANTS IN BRITISH MUSEUM 33 



thick mass of petrified phloem which is compared with the phloem 

 of recent conifers, but the unusual thickness of the tissue and its 

 composition are, I venture to think, features more suggestive of a 

 Cycadean alliance. 



In her definition of the genus Cycadeoidea of Buckland Dr. 

 Stopes states that the wood shows tw^o or more, and sometimes as 

 many as eight, concentric cylinders of secondary tracheids in 

 contrast to the single cylinder in stems of Bennettites (Cycadeoidea 

 of Ward and Wieland). Carruthers recognised, several years ago, 

 two cyhnders in Cycadeoidea Yatesii, a fact apparently overlooked 

 by Dr. Stopes. An interesting additional case of multiple cyhnders 

 is recorded in a new stem, Cycadeoidea Buzzardensis. It is claimed 

 that this power of forming more than one vascular cylinder con- 

 stitutes a feature distinguishing Cycadeoidea, as used by Dr. 

 Stopes, from Bennettites, the latter type being also characterised 

 by the short fertile shoots intercalated among the persistent leaf- 

 bases. It is pointed out that Buckland' s specimens of Cycadeoidea 

 from Portland are described by him as having more than one 

 woody zone, and his figure shows no signs of any cones among 

 the leaf-bases. Had Dr. Stopes consulted Buckland's later 

 account in the Bridgwater Treatise she would have seen that the 

 Portland stem is represented with several lateral " cones," a fact 

 which seriously affects her argument. My own view is that the 

 stems which she calls Cycadeoidea are practically indistinguishable 

 from Bucklandia, and it is certain that some at least of the stems 

 of this type bore Williamsonia flowers. 



The illustrations deserve a special word of praise. The volume 

 as a whole reaches a high standard, and the author is to be con- 

 gratulated on her handling of an extremely difficult piece of 

 research. A. C. Seward. 



Beitrdge ziir Kryptogamenflora der Schweiz. Band V, Heft 1. 

 Die Schweizerischen Protomycetaceen mit besonderer 

 Berlicksichtigung ihrer Entwicklungsgeschichte und Bio- 

 logie. By G. von Buren. Bern : K, J. Wyss. 1915. 

 95 pp., 28 text-figures, 7 plates. 10 fr. 

 This monograph is the first, as far as the reviewer is aware, 

 deahng with the Protomycetaceae, a group which is little under- 

 stood by most mycologists. It is certainly a matter of surprise to 

 find ninety-five pages devoted to them in a flora, but investigation 

 reveals the fact that only fifteen pages relate to the systematic 

 portion, the rest of the monograph concerning itself with the 

 morphology and biology of the group, a subject on which the 

 author has already published several short preliminary papers. 



According to Biiren the family contains four genera, Pro- 

 tomyces, Protomycopsis, Volkartia-'' (V. 2cmbelliferariwi and 

 V. rhcetica) and Taphridium ■'• [T. algeriense and T. immdatum, 

 neither of which species has yet been found in Switzerland). The 

 general account treats these genera separately. Over fifty pages 

 * As to the use of the generic names Volkartia, TapJiridimn and Mag- 

 nusiella, the present writer hopes to deal in a future number of this Journal. 



Journal op Botany. — Vol. 51. [January, 1916.] d 



