Notices respecting New Books. 147 



solutions through sand*, that they are probably of the same 

 origin; indeed the central cavity of the stalactite still remains 

 open in some of the specimens of this kind from Sweer's Island 

 in the Gulf of Carpentaria. The specimens from Madeira, pre- 

 sented to the Geological Society by Mr. Bowdich, and de- 

 scribed in his notes on that island f, appear upon examination 

 to be of the same character. — But there is no reason to suppose 

 that the trunks of trees, as well as other foreign substances, 

 may not be thus incrusted, since various foreign bodies, even 

 of artificial production, have been so found. Professor Buck- 

 land has mentioned a specimen of concreted limestone from 

 St. Helena, which contains the recent shell of a bird's egg J; 

 and M. Peron states that, in the concretional limestone rock 

 of the South Coast of New Holland, the trunks of trees occur, 

 with the vegetable structure so distinct as to leave no doubt as 

 to their nature <$. 



XIX. Notices respecting New Books. 

 Preparing for Publication. 



A TRANSLATION of the Baron Dupin's admirable 

 ~*- t Course of Mathematics applied to the Arts, and adapted 

 to the State of the Arts in England, by Dr. Birkbeck, Presi- 

 dent of the London Mechanics' Institution, is in the press and 

 will speedily be published in weekly numbers. Of all the writers 

 of elementary books, the Baron Dupin seems the most fasci- 

 nating. In the present work, — a transcript of his lectures, — he 

 has succeeded in making the study of mathematics extremely 

 amusing as well as instructive. Such a book has hitherto been 

 a great desideratum in our language, and must be very accept- 

 able to every student. 



ANALYSIS OF PERIODICAL WORKS ON NATURAL HISTORY. 



G. B. Sowerbifs Genera of Recent and Fossil Shells, No. XXIV. 



This Number contains the following genera : Oniscia, Py- 

 ramidella, Pyrida, Mactra, Lutraria, Tornatella. 



Oniscia is a new genus, distinguished from Cassidaria by its 

 granulated inner lip, its very short, scarcely reflected canal, 

 and its very singular general form. The species at present 



* Tubular concretions of ferruginous matter, irregularly ramifying through 

 sand, like the roots of trees, are described by Captain Lyon as occurring in 

 Africa. — Lyon's Travels, Appendix, p. 65. 



-f- Excursions in Madeira, 1825, p. 139, 140; and Bull, des Sciences Katu- 

 rel/es, vol. iv. p. 322. 



J Geol. Trans, vol. v. p. 479- § Peron, ii. p. 75. 



T 2 known 



