Miscellanies. 369 



42. Lethaa Geognostica of Prof. Bronn. Exchanges of objects of 

 Natural History. — We have mentioned with approbation the fine work 

 of Prof. Bronn on fossil organic remains, (Vol. xxxiii, p. 204.) 



By a letter received from him dated Heidelberg, October 26, 1838, 

 we learn that the first edition of the Lethsea Geognostica was already 

 exhausted even before the volume was finished. This volume has there- 

 fore been reprinted, an enlarged edition of the second volume has been 

 published, and a new edition is spoken of as necessary. 



The author being occupied with other labors and being anxious to cor- 

 rect all errors that may be discovered, to add to the text all new discove- 

 ries and a certain number of supplementary plates, so that the possessor 

 of the first or second edition shall have no occasion to purchase any thing 

 more than the additional text and plates ; for these reasons the new edi- 

 tion will not appear under from two to four years. It is not improbable 

 that a French edition will then appear. 



This will be an important acquisition, as many persons in countries 

 where the English language is spoken, can read works of science in 

 French who cannot read them in German. 



Prof Bronn having already arranged for exchanges on the part of the 

 Museum of Heidelberg with certain individuals in Boston, New York, 

 and Philadelphia, as far as regards birds, shells, and petrifactions, is still 

 desirous of effecting the same object in other branches of natural history, 

 especially for quadrupeds, insects, and reptiles. We beg leave to com- 

 mend this subject to the attention of our naturalists, not doubting (and 

 our own experience justifies the confidence) that they will receive a fair 

 and honorable equivalent for the objects they may send. 



The labors of Prof Bronn are worthy of all encouragement, and it 

 gives us pleasure to keep them in the view of our countrymen both on 

 account of their intrinsic value, and because the German savans are dis- 

 tinguished for their courteous and liberal treatment of this country. 



43. Prof. Agassiz on the Echinodermata.^ — The first Livraison of 

 this work has been kindly forwarded to us by the author. In Vol. xxxiv, 

 p. 212, we announced the intention of Prof Agassiz to publish it, and 

 are happy now to add our confirmation that it well maintains the envia- 

 ble reputation of the author of the Poissons Fossiles. 



In the introduction he recapitulates the facilities which he has enjoyed 

 in drawing up his history, from the liberality of all his scientific friends 

 on the continent and in England, in placing at his disposal their collec- 

 tions and labors in this department of Natural History. Speaking of the 



* Moiiographies D'Ecliinodermes Vivans et Fossiles, par L. Agassiz, ler Livrai- 

 son, contenant les Salenies. Neuchatel, Suisse — prix 10 frs de France ; subscriptions 

 received by A. Mayor, 8 Pine-street, New York. 



Vol. xxsvii. No. 2.— July-October, 1839. 47 



