Chapter 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 ═══════════════════════════════════════════════════════════════════════