Revieivs — Yorkshire Type Atnmonites. 547 



stimulated by the results of Wieland's study of a large number of 

 American fossil Cycadophytes, which were thought by some workers 

 to throw light upon the vexed question of the origin of the 

 Angiosperms. A full knowledge of these plants is thus particularly 

 desirable, and we must welcome descriptive work dealing with 

 them, even when — as is the case in the memoir before us — the 

 author has not been so fortunate as to add anything of material 

 importance to what was already known. 



The first section of Dr. Stopes' paper consists of a description of 

 a portion of a cone, Bennettites albianus, sp. nov., recently obtained 

 from the Gault of Folkestone Warren. The specimen was petrified 

 and proved suitable for sectioning. The author concludes that this 

 cone was " the giant fruit of the family". The fragment available, 

 however, measured only 5"5cm. x 3 cm. in transverse section, and 

 the idea that the cone was of peculiarly large size is deduced from 

 a reconstruction of its probable shape when complete; this may be 

 perfectly correct, but it must be regarded as at present scarcely 

 proven. The seeds with their embryos and seed-coats, and the 

 interseminal scales, are discussed and figured in detail. The author 

 describes the outermost layer of the seed covering as a " cupule " or 

 "aril" of elongated tabular cells. She regards the plug of tissue 

 closing the micropyle as nucellar in nature. 



Carruthers' type-specimen of Bennettites maximus has hitherto 

 been known only by its external characters, and so much of its 

 anatomy as could be observed with a liand lens. In the second part 

 of her paper Dr. Stopes records the results she has obtained by 

 having this specimen sectioned. The most notable feature is the 

 occurrence of extremely young cones. One of these, of which 

 preparations were obtained, shows in one section a collar of tissue 

 surrounding the jieduncle, which the author interprets as a whorl of 

 male sporophylls. She writes : " The discovery that this species had 

 hisporanc/iate cones is, of course, the feature of supreme interest in 

 the plant." When we consider, however, that the existence of 

 male sporophylls is deduced from a single section in which no 

 synangia are preserved, we can scarcely avoid feeling that, although 

 the truth of Dr. Stopes' view is highly probable, it must at present 

 be received with some degree of reserve, 



A. A. 



II. — YoEKSHiEE Type Ammonites. Edited by S. S. Btjckman ; 



photographs mainly by J. W. Txjtcher. Part XVI. 8 plates, 



and descriptions Nos. 112-116. London: Wesley. 1918. 



Price 35. od. net. 



rpHE present part of this most systematically edited publication 



JL deals with five Ammonite species : Arnioceras aemicostatus 



(Young & Bird) ; PerispJiindes ro^</^r (Williamson -Brown) ; Sildo- 



ceras bifrons (Bruguiere) ; Pachyceras n/yo-s?/s (Leckenby) ; Vertumni- 



ceras vertummis (Bean-Leckenby). This last is a new genus_of the 



family Cadoceratidse ; of the four paratypes of the species (which, 



with the holotype, are in the Sedgwick Museum) two are referred to 



