3.214, 
Lams d8 
$1.0 aan ($1.12 to Foreign Countries.) © 10cts, a copy. 
THe 
NAUTILU 
A MONTHLY 
DEVOTED TO THE INTERESTS 
OF CONCHOLOGISTS. 
ESTABLISHED BY W. D. AVERELL, IN 1886, AS 
«“ THE CONCHOLOGISTS’ EXCHANGE.” 
Mol. EET; DECEMBER, 1889 No. 8. 
CONTENTS: 
PAGE. 
DESCRIPTION OF A NEW AMERICAN HELIX. F.A.Sampson.  . : > Sp 
NOTES ON THE VARIATION OF CERTAIN MOLLUSCA INTRODUCED FROM 
EUROPE. T.D. A. Cockerell. : : ; ? : : 5 tele: 
Wat Is Species? Chas. T. Simpson. . : : : ‘ é 5 ie) 
On CREpPIDULA GLauca. John Ford. ‘ : : : : : 0 
THE SHELL-BEARING MOLLuscA OF RHODE IsLaND. Horace F. Carpenter. 92 
GENERAL NOTES. : 5 5 3 : ‘ ‘ ; : 5 - 9d 
Published by 
H. A. PILSBRY, Editor, Academy of Nat. Sciences, Philadelphia. 
W. D. AVERELL, Manager, Mt. Airy, Philad’a. 
Entered at Philadelphia Post-Office as second-class matter. 
FOREIGN AGENCIES :—London, Triibner & Co., 57 and 59 Ludgate Hill; 
Berlin, R. Friedlander & Son, 11 Carlstrasse. 
