THE HAMILTON ASSOCIATION. 87 



FRESH-WATER CONCHIFERA. 



Unio pressus, Lea. 



A few specimens from Dundas Marsh, May 6th. 

 Unio luteolus, Lam. 



Common in Hamilton Bay. A very variable species. 

 Unio complanatus, Sol. 



Very common in Hamilton Bay. 

 Unio nasutus, Say. 



A few specimens taken from Hamilton Bay. 

 Anodonta ovata, Say. 



A few specimens found in Dundas Marsh, May 6th. 

 Anodonta fluviatilis, Dillwyn. 



Common in Hamilton Bay. 

 Anodonta Benedictii, Lea. 

 Hamilton Bay. 



Several of these species were taken in abundance after 

 the severe storm of Jan. 9th last, along the shore of 

 one of the inlets of the bay near the city, and especially 

 imbedded in the ice near the shore ; specimens secured 

 having to be chopped out with a knife. Some single valves 

 taken at the same time and some on the shore at Port Dover 

 were of different species, but in too poor condition for 

 determination. 

 Sphcerium sulcatum, Lam. 



Hamilton Bay. A few specimens, differing somewhat, were 

 returned labelled S. sulcatum, var. 

 Sphcerium rhomboideum, Say. 

 Sphcerium stramineum. 



The latter two species were taken plentifully on May 6th 3 from 

 a muddy little creek running into the marsh near Dundas. 

 At an angle in its course there had been a wash-out, and the 

 bank just there was covered with these tiny bivalves. A 

 number of univalves were also found here. 

 Sphcerium occidentale, Prime. 



Plentiful in a small stream or run in open woods. May 13th. 

 Late in the summer more were taken alive from the dried up 

 bed of the same stream. 



