Misccilanics. 391 



that the aurora continued through the nighty and even to a late hour 

 this --'' 



morning. 



26- Transactions of the Geological Society of Pcnnsyhamay 



> 



Vol. I, Part 11. — In Vol. xxvii p. 347, we gave a notice of the 

 first part of this valuable work. The second part Is still more valu- 

 able, being replete with papers important alike to science and prac- 

 tical utilit)^ This part contains two hundred and fifty seven pages, 

 and is amply illustrated by plates : the entire volume contains four 

 hundred and twenty seven pages, and the execution is beautiful. 

 We are obliged to defer to another occasion, a particular notice of 

 the facts and views exhibited in this work, which does so much cred- 

 it to our science, that we hope and trust it will be continued ; not- 

 withstanding the difficulties, which (in common with all similar things 

 in this country,) we understand it encounters. 



27. Mr. ConracTs new work on American conchoJogy.* — The 

 natural history of the family of the Naiades of North America, illus- 

 trated by colored plates of each species; by T. A. Conrad, mem- 

 ber of the Academy of Natural Sciences of Philadelphia, honorary 

 Tneinber of the Geological Society of Pennsylvania. 



The author has made the Naiades the study of many years, and 

 it is his intention in this important work, to fix the names of the spe- 

 cies, in which he will be assisted by several able conchologists. 



All the figures will be drawn on stone by himself, from the best 

 and most characteristic specimens ; and the plates will be very care- 

 fully colored under his own immediate inspection. 



It may not be improper to state, that this is the only work of the 

 kind hitherto attempted, those species heretofore described being 

 scattered through various journals and other works. 



The work will be printed in royal octavo, on a new type, and 

 very superior paper. It will be issued in parts, each containing not 

 less than five finely colored plates, with accompanying descriptions 



of th 



e species 



The price per part, colored, will be one dollar. As some persons 



To be published by subscription, bj J. Dobson, Philadelphia, 



