JOURNAL AND PROCEEDINGS. 77 



I may have overlooked in the cases (they are very small), known as 

 the Mineralogist and Concholos^ist. The former by a process attaches 

 to the outer surface of the shell small pebbles, sand, etc., which it 

 collects ; the latter minute molluscs, which it affixes in a similar 

 fashion. They have a hard struggle against many enemies, and 

 perhaps nature has kindly furnished them with this means of con- 

 cealment. 



The top shells are largely represented in a fossilized state from 

 the lower Silurian Age. The rounded aperture of a few personally 

 obtained at Ancaster and from local rocks here at Hamilton, inde 

 pendent of other considerations, led the writer to infer they repre- 

 sented members of the Litorijiidic (Alga feeding shore shells). 

 When Naturalists, as you may perceive, find so much difficulty in 

 correctly classifying living Molluscs, we need scarcely feel surprised 

 at the still greater difficulties the patient Pateontologist encounters 

 when examining frequently mere casts or impressions of plants 

 which perished eons of ages ago, and who thinks himself fortunate 

 if he discovers, accidentally perhaps, the outlines of the aperture of 

 a Gasteropod filled with shale or muddy sediment, with other parts 

 of the shell concealed or embedded in hard limestone, which renders 

 it difficult of extraction in an unbroken slab. 



-From the mountain limestone in the south of Ireland the 

 writer has frequently obtained a Gasteropod, named Enoinphalus 

 pentangtdatus by Sowerby. It is represented by a Devonian form in 

 Ontario and in the calciferous (lower silurian) of Quebec, by Ophileta 

 Compacta. The specimen from the Irish carboniferous was described 

 as follows by the late Prof. Salter : 



" Shell depressed or discoidal, whorls angular, aperture 

 polygonal, umbilicus very large ; operculum shelly, round, multi- 

 spiral." It seems difficult to understand at first sight the reason 

 why Woodward classified it as "a top shell," but reflection shows 

 the leading characters. 



PYRAMIDELLID/E. 



" Owing to the circumstance that this family group, as a whole, 

 may be regarded rather as appertaining to past ages than the present 

 epoch," remarks Professor E. Forbes, Edinburgh, "they present 

 subjects of much interest to the student of extinct Molluscs." Very 



