262 Chronicles of Science. [April* 



Mr. Davidson's contribution to this volume consists of the com- 

 mencement of the Silurian portion of his monograph of British 

 Brachiopoda, and includes descriptions of the Silurnia species of the 

 families Lingulidse, Discinidse, Craniadse, and Spiriferidse. It is 

 prefaced by a bibliography of the subject, and by an essay on the 

 Classification of the Silurian Bocks, written by Sir B. I. Murchison. 

 As it requires a close study to appreciate this monograph, it is suffi- 

 cient to observe that it exhibits the scrupulous accuracy, both in 

 description and illustration, that is so characteristic of all Mr. David- 

 son's works. 



We think we perceive in this volume the evidence of some 

 additional care in the getting up and printing, more especially of 

 the plates ; those illustrating Dr. Duncan's monograph being very 

 favourable specimens of English lithography. 



In a former chronicle* we recorded the discovery near Mons, 

 by Messrs. Cornet and Briart, of a limestone containing Tertiary 

 fossils, apparently of Bracklesham age, beneath strata belonging to 

 the Systeme Landenien (Thanet sands). MM. Cornet and Briart 

 have since continued their researches, and have given the results 

 in a paper entitled " Notice sur l'Extension du Calcaire Grossier de 

 Mons dans la Yallee de la Haine."f Not only are they confirmed in 

 their original conclusion, but they are enabled to prove the exten- 

 sion of the fossiliferous deposit (calcaire grossier de Mons) for a 

 considerable distance. The weak part of the evidence, namely, the 

 proof of the age of the Landenian is not, however, strengthened by 

 this memoir. 



In a paper " On the Structure and Affinities of Lepidodendron 

 and Catamites" published in the ' Journal of Botany,' Mr. Carru- 

 thers has given his reasons for regarding these plants as Crypto- 

 gams, more highly organized than any existing members of the class ; 

 and for considering merely analogical, the arrangement of their 

 tissues to that of certain Gycadese and Cactacem. Mr. Carruthers 

 warns geologists against taking for granted " that the known con- 

 ditions of the living species of a genus are true also of the fossil 

 members of the same genus ; " and he cites the case of Elejihas 

 primigenius in illustration. This warning, coming from a botanist 

 writing on such a subject, should make geologists suspicious of the 

 probability of any of the numberless speculations on the climate 

 and conditions of the Coal-measure period. 



Dr. Hector, Director of the Geological Survey of Otago, has 

 published a 'First General Beport on the Coal Deposits of New- 

 Zealand,' the contents of which will probably surprise many unac- 

 quainted with the recent Government publications relating to the 

 geology of the colony. Both brown coal and true coal appear to 



* ' Quart. Jouvn. Science,' No. XI. p. 417. 



t 'Bull. Acad. Koy. Belgique,' 2 me serie, vol. xxii. 



