616 Beviews — Mesozoic Plants of England. 



volume gives a full account of the other English plants from the 

 Trias, Rhsetic, and Jurassic. With the exception of those from 

 the Stonesfield Slate of Oxfordshire and the Lias of Dorset, plant 

 remains are not at all abundant in any of these formations, and 

 such as occur are often fragmentary or ill-preserved. Thus, while 

 a number of the specimens dealt with in this volume have proved 

 unsatisfactory as records of the plant life of the period, their 

 elucidation, as far as it has proved possible, has added considerably 

 to what was previously known on this subject, and is therefore 

 highly valuable. 



After a brief discussion of the present state of our knowledge 

 of the earliest Mesozoic floras in various parts of the world, the 

 author passes on to describe in detail the few fragments of Triassic 

 and Rhastic age in the collection. The former period is represented 

 by only one plant remain, a seed known as Carpolithes sp. From 

 the Rhsetic, fragmentary specimens are referred to Equisetiles 

 Muensteri (a typical species of the period), Zycopodites lanceolatus, 

 and a fern Clathropteris platypliyUa. 



The Lias plants are represented by several specimens of the 

 following species among others : — Thinnfeldia rhomhoidalis, Cycadites 

 rectangidaris, Otozamites ohtusus, and Pagiopliyllmnperegrinum. Many 

 of these are well-preserved and fairly perfect specimens. A new 

 species of fossil wood is described as Cupressinoxylon Barberi, 



A special section is devoted to a discussion on the nature and 

 origin of Jet. It is sliown that in all probability Whitby jet has 

 been produced in large measure by the alteration of wood of the 

 Araucarian type. 



The collection from the Stonesfield Slate (Great Oolite) is the 

 largest described in this volume. It includes examples of Ginkgo 

 digitata and Baierd PhiUipsi ; several Cycadean fronds such as 

 Witliamsonia pecten, Zamites megapliyUus, as well as two new species, 

 Sphenozamites Belli and Fodozamites stonesfieldensis. Coniferous 

 remains, especially Thuites expansus, are also fairly abundant. 



Perhaps the most interesting specimen botanically is a leaf, 

 described as Phyllites sp., which in several respects closely resembles 

 that of a recent Dicotyledon. The author remarks that " had the 

 specimen been found in rocks known to contain the remains of 

 Angiosperms, there would be no hesitation in identifying it as 

 a leaf of a Dicotyledon ; but seeing that we know of no undoubted 

 Angiosperuious fossil in Jurassic strata, it is of the utmost importance 

 to demand satisfactory evidence before identifying a plant, or frag- 

 ment of a plant, as an Angiosperm." 



The remains from the Oxfordian, Corallian, and Kimeridgiau 

 are few in number, and consist for the most part of Coniferous 

 twigs or cones. 



The memoir concludes with tables of the geographic distribution 

 of the species described, and a short discussion on the botanical 

 features of these floras. A full bibliography is appended. 



