il THE NAUTILUS. 
STANDARD WORKS ON TCONCHOLOGM 
SOLD ONLY FOR CASH. 
STRUCTURAL AND SYSTEMATIC CONCHOLOGY. By Geo. W. Tryon, Jr. New, 
complete, plain edition. Illustrated. $16.00, postpaid. 
WGOODWARD’S MANUAL OF THE MOLLUSCA. Appendix by Ralph Tate. Last 
edition, $2.75, postpaid. 
KEEP’S WEST COAST SHELLS. A fascinating book for collectors, young and old. 
182 illusrations. 1.75, postpaid. 
BALDWIN’S LAND SHELLS OF THE HAWAIIAN ISLANDS. a5c., postpaid. 
WRIGHT’S CHECK LIST OF N. A. UNIONID/E, &c. 25c., postpaid. 
RANDOM NOTES ON NAT. HISTORY. Containing H. F. Carpenter’s article, ‘* The 
Shell-Bearing Mollusca of R.I.;’’ and Ritchie’s “* Check List of Shells.’’ Vol. 1, minus 
Nos: x and 2, 75c.; Vol. 2, 60c.; Vol. 3, 60c. Postpaid. 
THE CONCHOLOGISTS’ EXCHANGE. Back numbers. Vol. 1, minus No. 1, 50.3 
Vol. 2, Nos. 1 to 9, 35c. Postpaid. 
CONTRIBUTIONS to the Mollusca of Florida. By Chas. T. Simpson. Price 25c., postpaid. 
THE NATURALIST’S ASSISVANT. A Hand Book for the Collector and Student. 236 
pages, 4o illustrations, By J.S Kingsley. Price $1.50, post-paid. 
YOU CAN SAVE MONEY BY ORIERING SCIENTIFIC BOOKS FROM 
W. D. AVERELL, Mt. Airy, Phila., Pa. 
Nomenclature and Check-List 
AMERICAN LAND SHELLS. 
A list of United States Land Shells, complete to Sept., 1889, containing the 
and varieties with their habitats, prefaced by a brief discussion of their 
species 
nomenclature. 
Collectors interested in American Shells will find this a useful list for arranging 
and naming their collections, checking desiderata in making exchanges, etc. 
20 pages, Octavo, Price, single copies - 10 ects. 
es se “«¢ per dozen - 50 cts. 
Address: 
HA. PILSBigv. 
Academy of Natural Sciences, 
Logan Square, Philadelphia, Pa. 
