two drachms of gum arable or glim mastieh, did* 

 solved in two ounces of spirits of wine, will make 

 a light transparent varnish, easily to be washed 

 off. And to remove the outer coat of theTrochi, 

 or such as it may be the wish to preserve in an 

 uncoated state, the muriatic acid, diluted with 

 water according to the strength of the shell, may 

 be used ; and afterwards to give the highest lustre, 

 the manual operation of rubbing with pumice 

 stone, tripoli, or rotten-stone. Specimens should 

 also be collected in their different stages of growth ; 

 for the young of many shells have so different an 

 appearance from their full-grown state, as to be 

 often mistaken for distinct species. 



The more minute ones, as soon as they are 

 ascertained, may be fixed by gum water on blacH 

 or white cards, according to the opposition of their 

 colors, labelled with their generic and specific 

 names, and their exact habitats, with the addition 

 of v. or m. to signify whether they have been pro- 

 cured in a living or a dead state. 



It has also been our habit to place a mark in 

 the margin of the descriptive work we generally 

 use, against the species as it first occurred to us, 

 by which, at one view, we distinguish such as we 

 possess^ and such as are among our desiderata. 



CONCHO. 



