PRELIMINARY REMARKS. 7 



in the death of the artist Lawson, of Philadel- 

 phia, who fully understood the views of the au- 

 thor, and whose exquisite engravings are unsur- 

 passed by any thing of the kind extant. The 

 remaining plates were undertaken by Delarue, 

 of Paris, who was almost equally skilled and 

 successful. But he, too, died, and the work was 

 continued by artists trained by him ; their suc- 

 cess was but indifferent, and some of the plates 

 are so poorly engraved and colored that they are 

 admitted with great reluctance, and nothing but 

 the dread of further delay has deterred from 

 having them executed again. In justice to our- 

 selves, we must say, that our intentions to have 

 the work carried out as it was begun were most 

 sincere, and our efforts to succeed have been 

 most unwearied. For the serial irregularities in 

 the numbering of the plates, and for erroneous 

 references from the text to the figures, we must 

 express extreme regret, but will attempt no 

 apology. 



Meantime, new explorations have brought to 

 light new species, and have, in many instances, 

 induced modifications of the views expressed 

 concerning species previously known. Espec- 

 ially may this be said in relation to explorations 



