1841-42.] MONOGRAPHIE DBS ECHINODERMES. 179 



We have in these two letters a glimpse of Agassiz's 

 method of collecting specimens, making exchanges, and 

 disposing of his publications. 



The success of the " Fossiles du terrain cretace du 

 Jura Neuchatelois," of the " Prodrome d'une Mono- 

 graphic des Echinodermes," and of " Echinodermes fos- 

 siles de la Suisse," all published at the expense of the 

 Societe des Sciences Naturelles de Neuchatel and of 

 the Societe Helvetique des Sciences Naturelles, led 

 Agassiz to undertake, at his own expense, the publica- 



r 



tion of " Monographies d' Echinodermes vivants et fos- 

 siles," with many beautifully executed plates. It was 

 an unfortunate undertaking, very expensive on account 

 of the great number of plates, and without proper pat- 

 ronage from naturalists to make it profitable. Only four 

 monographs or " livraisons " were issued between 1838 

 and 1842. The first, on "Salenies," 1838, shows good 

 work, and is very creditable in all respects, and worthy 

 of the name which signs it ; the second, on " Scutelles ' 

 (July, 1841), although containing many new facts and 

 an interesting history of the progress of the natural 

 history of the echinoderms, besides twenty-seven most 

 exact and beautiful plates, did not attract much at- 

 tention ; while the third " livraison," containing the 

 "Galerites" and " Dysaster " (1842), is by E. Desor. 

 Agassiz helped in the revision of the proof-sheets ; 

 but, on the whole, the work shows a noticeable inferi- 

 ority to all the previous publications on the echino- 

 derms. 



The fourth "livraison' (1842), the manuscript of 

 which was written in German and translated into 



