Introductory 11 



in the collection, among the Cones for example, range 

 in cost from twenty to seventy-five dollars apiece. 

 But where there are so many that are rare and costly, 

 the selection of a few prominent names is difficult. 

 It is invidious to the many to name a few. Looking 

 from the opposite view-point, Ave find that no common 

 species has been omitted or excluded. On the con- 

 trary, the common and well-known are represented 

 by the finest specimens and fullest suites of variations. 

 The best of the molluscan democracy are beside the 

 aristocracy. There is thus a remarkably complete and 

 select general collection. Indeed, it might be said of 

 the marine shells that it were much easier to list the 

 few missing forms than to catalogue those present. 

 Many genera are complete, while other large ones lack 

 but one or two species. 



The full significance of Mrs. Williams' life-work 

 appears when we add to this commanding array of 

 typical and well-known forms (with rare and unmatch- 

 able things in all groups), many special series such as 

 fine mutational suites and geographical assemblages, 

 a large number of Tertiary fossils, particularly Cypraei- 

 dae, many newly-described land and fresh-water shells 

 of Japan, a good showing of deep-sea species, the re- 

 markable halolimnic forms from Lake Tanganyika 

 and many other factors that usually mark a great 

 museum collection built upon unlimited resources. 

 No feature of pure conchological science that can find 

 expression in a collection has been overlooked, indeed, 



