Assertion: individual snail | /r/AtLocation | the undersides of flat rocks
Facets:
value: in the river's shoals
type: LOCATION
value: in riffles
type: LOCATION
Source sentences:
text: He noted that the snails appeared "in vast abundance," with 20 or 30 individual snails attached to the undersides of flat rocks in the river's shoals and riffles.