128 Reviews — Weaklen Plants in British Museum. 



Flora. It is remarkable, however, to find how little evidence there 

 is to prove that these various remains really belonged to plants like 

 the Cycads of the present day. As the author says (p. 240) : " We 

 must remember that the so-called Cycadean fronds from Mesozoic 

 rocks are nearly always found apart from the stems and reproductive 

 structures, and we are still to a large extent in the dark as to the 

 exact nature and structure of these extinct Cycadean plants." 



In his introductory remarks Mr. Seward points out the 

 frequent difficulty in distinguishing for certain between leaves of 

 ferns and Cycadacea?, and briefly discusses the evidence for the 

 existence of Palaeozoic members of the latter family. Some of the 

 Carboniferous specimens, such as Pterophyllum Fayoli, Ren. and 

 Zeill., have, he thinks, a strong claim to be regarded as Cycadean 

 plants. Among the beautiful fronds from the Wealden figured in 

 this book, many, and notably those referred to Cycadites and 

 Dioonites, show a striking similarity to the leaves of recent genera. 

 As regards Cycadites, the author indicates certain sources of error 

 in determining whether the pinna has a single vein, the most critical 

 point in determining the relation to the genus Cycas. No one can 

 doubt the Cycadean affinities of the fronds and stems described here 

 (with the exception of such doubtful genera as Nilssonia and Auomo- 

 zamites). The difficulty is that fructifications are rare, and those 

 which we know best (Bennett ites) are quite different from any 

 flowers of recent Cycads. Thus, we can never say for certain 

 whether a given fossil, with Cycadean habit, really belonged to 

 the family Cycadaceas, in the comparatively narrow sense of recent 

 Botany, or to the Bennettitese, a related, but perfectly distinct group. 



The author recognizes scarcely any characteristic Cycadean fructi- 

 fications among the specimens examined by him. So doubtful is 

 he about forms hitherto referred to Cycadeosfrobus, that he revives 

 Sternberg's old genus Conites for their reception, thus avoiding any 

 expression of opinion as to their true position. The only example of 

 a true Cycadean fructification described is Androstrohus Nathorstii, 

 sp. nov., which bears much resemblance to a male flower of this 

 family, and in some specimens shows with great clearness the scars 

 of numerous pollen-sacs on the lower surface of the scales. 



Among stems of Cycadean habit, a new species of Fittonia is 

 described, with the leaf-bases remarkably well preserved. The 

 author regards certain Wealden stems formerly referred to Dracana 

 as being much more probably Cycadean, and points out their re- 

 semblance to some species of Zamia. He finds no evidence for the 

 existence of Monocotyledons in the English Wealden. 



A full account is given of that most interesting of all Mesozoic 

 genera, Benneitites, which the author identifies with Williamsonia. 

 The internal structure of the fructification of this extraordinary 

 plant, which, to a certain extent, combines Cycadean with Angi<>- 

 spermous characters, is now well known owing to the classical 

 researches of Carruthers and Solms-Laubach, and, more recently, those 

 of Lignier. The author descrihes some ver}' interesting specimens 

 from the Wealden, which he refers to another species, B Carr nth' i si. 



