Reviews — A New Russian Review. 177 



termed Acrodonchus. It may be convenient for stratigraphical pur- 

 poses to have provisional names for such fossils ; but, as they possess 

 no biological significance, we venture to think they are an un- 

 fortunate burden to scientific nomenclature. Moreover, in the 

 present instance, the names proposed result from an imperfect 

 acquaintance with previous researches. The term Sphenonchus was 

 originally applied by Agassiz, not to the later Jurassic spines that 

 prove to belong to Aster acanthus, but to the spines of Hybodus and 

 Acrodus from the Lower Lias of Lyme Regis — a formation in which 

 Asteracanthus has never been discovered. Again, the specimens in 

 the British Museum show that there is no constant difference between 

 the cephalic spines of Hybodus and Acrodus ; and the true nature of 

 these fossils is far from being a recent discovery, as reference to 

 Mr. Charlesworth's paper of 1839, and Mr. Day's note of 1865, will 

 show. If a provisional generic name of any kind be adopted, that 

 of Sphenonchus thus has priority, while Hybodonchus and Acrodon- 

 chus are mere synonyms. A. S. W. 



V. — An Elementary Text-Book of Geology : intended as an 

 Introduction to the Study op the Rocks and their Contents. 

 By W. Jerome Harrison, F.G.S. (London, Blackie & Co., 

 1889.) Small 8vo. pp. 200. Price 2s. 6d. 



THIS little work may be recommended as giving a concise 

 account of the leading geological facts, under the divisions of 

 Descriptive Geology, Palaeontology, and Historical or Stratigraphical 

 Geology. It will be useful as an elementary class-book for students, 

 and as an introduction to the larger manuals. 



A new Russian Review. 

 VI. — "Revue des Sciences Naturelles." Societe des Naturalistes, 

 Universite, St. Petersburg. (Annual subscription, 8 roubles 

 50 kopeks.) 



ALTHOUGH Nikltln's admirable " Bibliotheque geologique de la 

 Russie " enables geologists to obtain access to Russian literature 

 more readily than can workers in other departments of natural 

 science, nevertheless the publication of a monthly, in addition to an 

 annual list, cannot fail to be welcome. Hence geologists will be 

 interested in the success of the latest addition to Russian periodical 

 literature — the VyestnTk Estestvoznaniya, recently commenced by 

 the St. Petersburg Society of Naturalists. This review will consist 

 of original articles on various branches of natural science, with short 

 French abstracts, and a bibliography, also in French, of Russian 

 scientific literature; the first number, which has just been issued, 

 including three geological articles, viz. a paper by Levinson- 

 Lessing on " Some Chemical Types of Eruptive Rocks," a report by 

 P. N. Venyukov on the Devonian beds of Mughodzhares, and a 

 criticism by B. Polyenov on Michel Levy's " Structure et classi- 

 fication des roches eruptive." 



The new journal is edited by the veteran physiologist F. V. 



DECADE III. — VOL. VII. NO. IV. 12 



