Transcriber’s Note:

The cover image was created by the transcriber and is placed in the public domain.

$2.00 per Year.($2.20 to Foreign Countries.)50 cts. a copy

THE
NAUTILUS
A QUARTERLY
DEVOTED TO THE INTERESTS
OF CONCHOLOGISTS

EDITORS AND PUBLISHERS:
H. A. Pilsbry, Special Curator of the Department of Mollusca, Academy of Natural Sciences, Philadelphia.
C. W. Johnson, Curator of the Boston Society of Natural History.
Vol. XXXI.OCTOBER, 1917.No. 2

CONTENTS:

Notes on the variation of Ischnochiton conspicuus. By E. P. Chace[37]
Lampsilis ventricosa cohongoronta in the Potomac River. By Wm. A. Marshall[40]
Collecting about Guantanamo Bay, Cuba. By John B. Henderson[41]
Amnicolidæ from Oneida Lake, N. Y. By H. A. Pilsbry[44]
New Genera and Species of Central American Naiades. By L. S. Frierson[47]
On the rate of growth of pond Unios. By L. S. Frierson[49]
A new South African Nesopupa. By H. A. Pilsbry[50]
A new Gundlachia from Guatemala. By Bryant Walker[51]
A list of shells from the East Coast of Florida. By Bryant Walker[53]
Collecting in Digby, Nova Scotia. By Lilian Dyer Thompson[57]
A new type of the naiad-genus Fusconaia. By A. E. Ortmann[58]
The Relation of snail fauna to floods. By A. Richards[64]
William Bullock Clark[68]
Publications received[69]
Notes[71]

C. W. JOHNSON, Business Manager,

Boston Society of Natural History,

Berkeley Street,