No. 4.] DAWSON — POST-PLIOCENE. 383 



Recent — Murray Bay and Cacouna ; precisely similar to the 

 shells from the Post-pliocene. Also Greenland (Moller) ; La- 

 brador (Packard) ; and south to Cape Cod. 



Modiolaria discors, Leach. 



Fossil — Beauport, of good size; Greenland (Moller). 



Recent — Labrador to New England. Specimens from Gasp^ 

 are precisely similar to the fossil. This shell is no doubt identi- 

 cal with M. loevigata of Gray, and possibly with the M. dlscre- 

 paiis of some other authors. It is however the same with that 

 figured in Binney's Gould as M. discors. 



Crenella glandula, Totten. 



This species, which is at present quite common in the Gulf St. 

 Lawrence, is indicated in my formerly published lists as a Mont- 

 real fossil ; but I have mislaid the specimens, and cannot there- 

 fore now repeat the comparisons with the recent shells. 



According to Mr. Whiteaves this is quite distinct from C. decus- 

 sata, Montagu, both being found living in Gaspe. 



Nucida tenuis^ Montagu. 



Fossil — Leda clay, Montreal ; Saco (var. inflata) ; Rivi^re-du- 

 Loup ? 



Recent — North shore Gulf St. Lawrence to Gaspe (Whiteaves) 

 type and var. inflata ; also European coasts. 



N. expansa, Reeve. 



Fossil — Leda clay and Boulder clay, Riviere-du-Loup ; Saco ; 

 Duck Cove, St. John, N.B. 



Recent — Labrador (Packard) ; Murray Bay ; Arctic seas. 



I doubt if this is not a large and well-developed northern form 

 of AT. tenuis, 



N. antiqua, Morch, from Leda clay of Maine, seems to be a 

 variety. 



Leda permda, Muller. 



Fossil — Leda clay, Riviere-du-Loup ; Portland; Saco; Law- 

 lor's Lake, N.B. (Matthew). 



Recent — Arctic seas and south to New England. 



This shell occurs very abundantly at Riviere-du-Loup ; and 

 the specimens found there show that no specific line can be 

 drawn between the forms known us permda, buccata (Steenst.), 



