198 PROCEEDrNGS OF THE MALACOLOGICAL SOCIETY. 



namely : that a great many forms probably became extinct, because 

 tbey could not change and adapt themselves to new external conditions. 



2. Another series have from early times selected for themselves 

 special habitats so peculiar and unlike those of the rest of their class, 

 that they have as a consequence become in a sense retrogaded and 

 deteriorated by their surroundings so as to lose caste, as it were, in 

 the Molluscan sub-kingdom {e.g. parasitic, sedentary, and boring 

 forms, and some of the burrowing and coral-dwelling forms). 



3. On the other hand, we also see that a considerable number of the 

 Palaeozoic and ^Mesozoic types have survived to our own day, and, 

 although they may have become extinct in the regions where they 

 once were abundant, they still linger on, in diminished numbers, in 

 out-of-the-way localities, where the hostile influences have proved to 

 be less severe.' 



I must now conclude these scattered notes, which, from their 

 mixed and fragmentary character, may be compared to a haul of the 

 naturalist's dredge, and like it, too, may perhaps serve to convey to 

 you, in some slight degree, the wealth of material that lies below, 

 and which only requires to be brought to the surface out of the vast, 

 but little explored, literary sea. In both these directions it will be 

 your duty, as I am sure it will also prove your pleasure, as members 

 of this Society, to extend your explorations, and to record in our 

 " Proceedings" your observations in the near future per mare et terris. 



*- :*!*** 



" For the sea, too, seeks and rejoices. 

 Gains, and loses, and gains. 



And the joy of her heart's own choice is 

 As our's, and as our's are her pains." 



(Sea and Shore.) 



' For example, Chrysoclomus contrarius, so abundant a fossil in the Red Crag, 

 is still found living in Vigo Bay, off the coast of Spain. 



