38 Post-Pliocene Deposits of the St. Lawrence. 



Figs. 18 and 19. — Joints of Ophiocoma, magnified. 



Modiola glandula. — A single valve of this pretty lttle shell 

 has been found at Logan's farm. It now inhabits deep water in 

 the Gulf of St. Lawrence. I may also mention that I have found 

 perfect specimens of Modiolaria discors both at Logan's farm and 

 Beauport, which quite confirm Dr. Gould's identification of my 

 fragment of last year with that species. 



Fusus (Clavatula) turricula. — Specimens of this shell have 

 been found by Mr. R. Ramsay at the Brick-yards at the Tanneries. 

 It occurs extensively in the North Atlantic, and fossil in the 

 British Crag. 



Rissoa. — Since the publication of my last paper, Mr. Bell of the 

 Geological Survey, has shewn to me in that collection a Rissoa 

 with five distinct revolving bands, separated by a flattish space 

 from the suture. On comparison of this shell with my specimens 

 referred last year to R. minuta, I am inclined to think that they 

 are the same, but that the latter were worn, so as to present a 

 smooth surface. It is not unlike R. obsoleta of Wood's Crag 

 Mollusca. I have another little shell which closely resembles 

 Alvania ascaris of the same author, but it is too incomplete for 

 its certain identification. 



Spirorbis spirillum. — This common species is found of small 

 size, attached to pebbles, at Beauport. 



V. General Remarks. 



In so far as general conclusions in Geology are concerned, the 

 observations of the past year do not in any way conflict with the 

 conclusions stated in my former paper. 



The arrangement of the deposits at Logan's farm and Beauport, 

 confirms the subdivision which I have attempted to establish, of 

 an underlying non-fossiliferous boulder clay, a deep-water bed of 

 clay or sand (the Leda clay of Montreal), and overlying shallow- 

 water sands and gravels, the Saxicava sand of my former paper. 

 This arrangement shows a gradual upheaval of the land from it* 



