numerous casts of fossil bivalves , but unrecognizable in a coarse sandstone. ((the following parenthetical statement added later by JH “(these are casts of concretions)”)). The Fountain extends well across the west valley at Chimney Hollow . Carter Lake has no outlet now. It may be due either to deformation or an outwash dame of debris, probably the former. Old terraces indicate that the water once rose some feet higher and that at one time there was an outlet at the S end. The S barrier is not now very high. In afternoon I collected fossils in the Benton. Found Inoceramus cf. I. labiatus just below middle of formation, with undetermined cephalopods and an undescribed oyster found near Boulder and west of Ft. Collins . In two or three thin limestones in the upper half of the formation I found the usual abundance of I. labiatus and a few cephalopods . Reached