APRIL 15, 1914. 
{ 
PROCEEDINGS 
OF THE 
Vou. I, p. 30, 
THOREAU MUSEUM OF NATURAL HISTORY. 
MIDDLESEX SCHOOL, 
CONCORD, MASSACHUSETTS. / 
A LIST OF MOLLUSCA COLLECTED AT 
CONCORD, MASS. 
BY D. C. HAWKINS. 
The following isa preliminary list of Shells from Concord, 
Massachusetts, collected since 1901. 
This list comprises about 
one-third of the species that should be found in the township. All 
the specimens here given are represented in the collection of the 
Thoreau Museum of Natural History, and were determined through 
the kindness of Mr. C. W. Johnson of the Boston Society of Nat- 
ural History. 
Family: 
Family: 
Family: 
Family: 
Family: 
Family: 
Family: 
Family: 
Family: 
MOLLUSCA. 
Unionidae. Fresh-water mussels. 
Anodonta cataracta Say. 
Anodonta wmplicata Say. 
Unio complanatus Sol. 
Lampsilis radiatus’ Gmel. 
Viviparidae. Fresh-water snails. 
Campeloma desisa Say. 
Lymnaeidae. Pond-snails. 
Planorbis campanulatus Say. 
Physidae. Sinistral-formed pond-snails. 
Physa heterostropha Say. 
Succineidae. Amber-snails. 
Succinia ovalis Say. 
Succinia ovalis var. totteniana Lea. 
Helicidae. Garden snails. 
Polygyra albolabris Say. 
Philomycidae. Shell-less slugs. 
Philomycus carolinensis Bose. 
Limacidae. Internally shelled slugs. 
Limax flavus Linn. 
Agriolimax agrestis Linn. 
Zonitidae. Externally shelled snails. 
Zonitoides arboreus Say. 
