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INSECTS. 
Corixa interrupta. Water-boatman. 
Notonecta undulata. Back-swimmer. 
Zattha fluminea. Water-bug. 
Limnotrechus marginatus. Water-strider. 
Mollusks were very abundant in this pond, especially the larger 
species. Only a few individuals of two or three species (MVusculium, 
Physa, Lymnea) were found in the central cattail area, the major- 
ity being found about the edges of the pond near the button-bushes, 
where they had taken refuge beneath the wet leaves and grass when 
the water disappeared. Under decaying logs and about the roots 
of the shrubs were the best localities for the majority of the species. 
The Lymnzas were abundant under damp vegetation at the east end 
of the pond (July—August). In this wet situation the Lymnzas, as 
well as some Physas and a few Musculiums, are able to survive 
the long dry summer and are ready to revive when the fall rains 
‘begin. 
The following species of mollusks were secured in this pond. 
FLUVIATILE SPECIES, 
Spherium occidentale. Not common. 
Musculium partumetum. Common. 
Physa gyrina. Common. 
Segmentina armigera. Common. 
Planorbis exacuous. Common. 
Lymnea reflexa. Common. 
LAND SPECIES, 
Succinea avara. Rare. 
STATION XVII. 
A small depression about 100 feet southwest of Station XVI, 
thirty feet or more in diameter. The arboreal vegetation in and 
about this spot is as follows. 
Ostrya virginiana. Hop Hornbeam. 
Cephalanthus occidentalis. Button-bush. 
Quercus bicolor. Swamp White Oak. 
Carya ovata. Shellbark Hickory. 
