42 On the occurrence of Freshwater Shells 



Hermes maculatus. Common, flying by day in July the whole way up the 

 Rouge. I have also taken it at Sorel, and it occurs in the Eastern 

 Townships. It generally hovers over the water. 



Panorpa subfurcata. Observed at Bevin's Lake, Montcalm ; Huckleberry 

 Rapids, De Salaberry ; and Hamilton's Farm ; July to September. 



Although the Diptera are so very numerous, not only in species 

 but in individuals, that they are without exaggeration the worst 

 evils of back-woods life, witness the various species of " Deer-fly " 

 (Tabanus) J Golden-eye (^Chrysops), ''Black-fly" [Simulium), Mos' 

 quito (^Culex), and " Sand-fly," all of which are more or less 

 annoying. I am sorry to say I collected but a few specimens 

 some of which were destroyed and most of the others I have 

 been unable to determine. 



The Hymenoptera collected will be noticed elsewhere. 



Exeter, Devonshire, June 2nd, 1860. 



ARTICLE ly. — On the occurrence of Freshwater Shells in some 

 of our Post Tertiary Deposits. By Robert Bell. 



(Presented to the Natural History Society of Montreal.) 



The various deposits described in the following paper are of 

 diflfereut ages and have been formed under very difierent circum- 

 stances, but are arranged under the same head for the sake of 

 convenience. 



Montreal. 



Early in the spring of 1858 I accompanied Mr. D'Urban, who 

 has done much for the cause of Natural History in Canada, on 

 several excursions to collect fossils at the localities in the vicinity 

 of Montreal where drift shells had been discovered. In examin- 

 ing the sides of Mr. Peel's clay pits, which are excavated in the 

 120 feet terrace, we discovered a few specimens of Limncea cape- 

 rata^ Say, in place, in a thin layer of sand immediately above the 

 Leda clay and more than three feet below the surface of the 

 ground, which is level at the place. In the same bed with these 

 fresh water shells Saxicava rugosa^ Tellina greenlandica^ Mya 

 arenaria, Mya truncata and Mytilis edulis are associated ; and in 

 the clay immediately underlying it Leda Portlandica was found, 

 but not in any abundance. 



About the same time that this Limnsea was found at Mr. PeePs 



