ERRATA. 



The reader is requested to correct the following errata in Vol. XXX. of the 

 American Journal of Science. The writer of that article, at the time of its pub- 

 lication was in the Indian country, on Red river, several hundred miles west of 

 the Mississippi, where the proof sheets could not be sent to him; and it is only 

 since his return from that part of the country, that he has seen the article in print. 

 There are several errors in punctuation, but the verbal errors only will be noticed. 



W. W. Mather, Mining Engineer. 



P. 326, 1. 3 fr. bot. for quality, read equality. — P. 328, 1. 9 fr. top, for exhaustible, 

 read expansible; 1. 11 fr. top, for %oill thrust, read will be thrust. — P. 329, 1. 7 fr. 

 top, for ^/tose, read that. . 



Vol. XXXII.— P. 273, 1. 5 fr. top, for 9, read 266 — P. 290, 1. 17 fr. top, for oppo- 

 site, read preceding. 



CORRECTION. 



In Prof. Green's notice of Trilobites, in this No. p. 169, for Asaphus Platypleu- 

 rus, read Trimerus Platypleurus, this correction being made in consequence of 

 the examination of more specimens from the same locality. 



