100 Molluscs of the isles Sechelles and Amirantes. 



put them immediately into a conservative liquid, as is almost 

 exclusively done by most travellers ? It was necessary to 

 pass days, months, and entire years to observe these crea- 

 tures carefully in all their peculiarities. 



Without doubt the labour of M. Dufo is not a work 

 essentially scientific, its author has not had the pretension, 

 but they are elements of true importance, first in them- 

 selves, and secondly because of their variety, which will 

 serve not a little to enrich the works of naturalists and the 

 collections of our Museums.* 



We therefore propose that the Academy address its thanks 

 to M. Dufo for the zeal which he has manifested in accom- 

 plishing a mission which was self-imposed, by inviting him to 

 continue it, if possible, in which case, to direct his attention 

 to the creatures themselves in their relation with their shell, 

 on the difference of sex, on the ova of each species; points 

 yet very little advanced in the history of molluscous animals, 

 but which must have a great influence on the progress of 

 science. 



* We presume it will give pleasure to zoologists when we announce 

 that M. Dufo was quite anxious to present the whole of his beautiful 

 collection to the administration of the Museum. 



