50 Murchisoris Silurian System. 



rocks have remained, says Mr. Murchison, so clear, that the 

 geologist has in them a record never to be mistaken. Thus 

 Professor Sedgwick has pointed out bands of prophyry 

 interstratified with slates, the whole of which have been 

 subsequently pierced by other intrusive masses of igneous 

 origin, thus evincing two widely different periods of igneous 



action. 



[To be continued.] 



Dr. Wight's Illustrations of Indian Botany. 



We have recently received the xmth No. of the " Illus- 

 trations of Indian Botany," by Dr. Wight, and the xmth and 

 xivth Nos. of " Icones Plantarum Indias Orientalis." The 

 object of these works is, as our readers are aware, to supply 

 the means of reference to the student in Indian Botany at 

 the cheapest possible rate, consistently with due accuracy of 

 the plates, which are necessarily very numerous. 



The first is intended, as the author expresses it, to ex- 

 plain the principles of grouping plants according to their 

 natural affinities, and illustrating these by figures of each 

 group. The second is intended to afford figures of Indian 

 plants described in the author's " Prodromus Florae Peninsula? 

 Ind. Orientali," an octavo work in two volumes, containing 

 more information on the subject of Indian Botany than all the 

 costly quarto, atlas, and folio volumes that have been hitherto 

 published, with this additional advantage — that it may be had 

 for ten rupees. Even the " Icones" intended to illustrate the 

 " Prodromus" appears in monthly numbers, each containing 

 ten quarto plates, lithographed under the author's eye for one 

 or two rupees. The grand object being to give to India, so 

 far as the limited resources of a private individual will permit, 

 that which England has so long enjoyed in " Smith's English 

 Botany," — a standard work of reference, at the lowest possi- 

 ble price. 



With the " Prodromus" and the two works now in course of 

 publication, the student would be in possession of a botanical 



