418 Newer Pliocene c(,nd Post Pliocene Deposits. 



I have received a specimen from Chicoutiwi, Gaspe, from a 

 littoral deposit a few feet above the level of the high tide, con- 

 taining Saxicava rugosa, Balanus hameri, and Natica clausa- 

 Recent American coast, (Lit.) 



^Margarita ArcticOy Gould, (M. helecina, Moll,) Montreal 

 with Fusus, &c. Some of the specimens are of large size and 

 may be detected even when in fragments by their pearly appear- 

 ance. Recent Cape Cod and Northward, (Lit. Lam.) 



* Lacuna neritoidea, Gould. A single specimen with Fusus, 

 Ac, Montreal. Recent on New England ooast.(Lit. Lam.) (Fig. 29.) 



^Acmaea, (Propilidiura,) Caeca, Mon. (Fig. 9.,) (P. Candida, 

 Couthouy,) Montreal, with Fusus, &c. ■ The specimens are of 

 laro-er size than recent. This is probably the shell figured in N. 

 Y. Reports as Patella. Recent Cape Cod and northward, also 

 Greenland, Finmark, Spibergen. (Coral, D. S. Cor.) 



*Amicula vestita, Gray. (Fig. 24.) (Chiton Emersonii, Gould.) 

 With Fusus, &c., at Montreal. Recent Cape Cod. and northward. 

 (Cor.) 



Acephela. 



Saxicava rugosa, Lam. (Fig. Can. Nat. vol. 1.) This is the 

 most abundant shell in the littoral deposits at Montreal, Beauport, 

 &c. Though not strictly, a littoral shell, it was prjbably driven 

 to the beach by breakers acting on the stony bottom of drift, or 

 on the ledges of shale and limestone, in which it sheltered itself. 

 At Beauport the size is small, and this is also the ease at Green's 

 Creek and the higher levels at Montreal ; but at Logan's Farni 

 and at St. Nicholas, these shells are as large as any modern 

 specimens that I have seen. On the surfaces of drift and Leda 

 clay this species seems, as on the American coast at present, to 

 have sheltered itself among stones and in patches of sea weed and 

 mussels ; but from the abundance of perforated pieces of limestone, 

 I suspect that it also burrowed in the softer submerged ledges, and 

 that this may account in part for its great abundance. At pre- 

 sent this shell is generally distributed over the North Atlantic, 

 It ranges from low water to great depths, and is of larger size in 

 the Arctic Seas and in deep water. 



Mya arenaria, lAnn. Abundant at Montreal^; but always of 

 small size, rarely more than half the size of recent shells from the 

 o-ulf of St. Lawrence ; but there are in C. G. S. very large and 

 thick specimens from a raised beach at Rivi6re du Loup. (Lit.) 



