iO THE NAUTILUS. 



Here also, near the center of the west gallery, are located the cases 

 intended for a special collection of all molluscous species belonging 

 to the United States. 



The idea of this collection emanated from the President of the 

 American Association of Conchologists and there is every reason to 

 believe that the members will agree with him and show their apprecia- 

 tion of the project in offerings of the best specimens obtainable near 

 their respective homes. Just beyond these, in cases and drawers, 

 can be seen a majority of all the fresh water species of the world, 

 including the types of Rafinesque, Say, Conrad, Tryon, Haldeman 

 Gabb and others, and a series of duplicate types of Lea's Unionidse. 



The series of Land Shells commences with Oleaclna, a genus 

 chiefly confined to the U. S. Gulf States and Central and South 

 America. A majority of the species are shown, and as many of the 

 shells are translucent, the visitor, for this and other reasons, will find 

 them both interesting and instructive. 



The same translucent, and in some instances transparent, character 

 is also finely illustrated among species of Vitrina in a case near by. 

 Just beyond the latter are several families containing a compara- 

 tively large number of genera. Of these the most familiar are Gib- 

 bus, Zonites and Nanina, the arrangement of which is entirely com- 

 pleted, a task that only expert conchologists can fully appreciate. 

 In Zonites and Nanina many beautiful gems are presented, though 

 none so singular in form, perhaps, as are the species Lyonettianiis and 

 pagodus in the genus Gibbus. 



Next come the typical Helices, a genus containing some 3,400 spe- 

 cies. An enormous number indeed to be of one kin. Among those 

 exhibited are many specimens remarkable for size, perfection of fin- 

 ish, and the rare combination of colors adorning their surfaces. 

 With these can be seen H. pieta, from Cuba, with its forty color 

 varieties, each " a thing of beauty and a joy forever ;" H. Gibboni 

 with its white and chestnut-colored crescents ; and H. Pohjgyrata 

 whose many whorls are alike suggestive of giddiness and French 

 horns. Also scores of others no less enchanting though hailing, with 

 their less favored brothers, from all continents and islands of the 

 world. In the same family is that wonderful group known as the 

 Cochlostyla. This comprises many sub-genera, including the typical 

 Cochlostylns of Ferrussac. The group, however, as it is understood, 

 embraces nearly all of the Helicoid and Bulimiform land species 

 belonging to the Philippine and adjacent islands. 



