THE ANNALS 



AND 



MAGAZINE OF NATURAL HISTORY. 



[FOURTH SERIES.] 

 No. 113. MAY 1877. 



XXXV. — Malacological Notes. 

 By Robert Garner, F.L.S. &c. 



It seems to be a task neither easy nor free from doubt, to 

 assign a proper place in the Animal Kingdom to the Mollusca, 

 or, when their proper place is found, to fix their boundaries as 

 a subkingdom. It is evident that animals, both as they exist 

 now and as they have succeeded each other in past geological 

 time, are marked by different degrees of elaboration ; and this 

 leaves room for the doctrine of derivation from simpler pri- 

 mordial forms of the higher. This increasing differentiation 

 in the animal kingdom is also tacitly kept in view in taxonorayj 

 hence Mammalia are placed highest in the whole animal series, 

 and Mollusca in the non-vertebrate division of it. 



But the above greater or less elaboration, though a primary 

 consideration in general classification, is not by any means 

 the sole one. Were it so, and were we assured that one of 

 the higher forms is descended by an undeviating development 

 from one of the simpler, we ought to have, tracing the former 

 through the course of its formation, a summary of all orga- 

 nology, which we have not. Strong are the influences which 

 the conditions of life (ethological as they are termed) exert on 

 the course of development ; or, in other words, great are the 

 variations necessary to modify an organism for change of 

 habitat, food, or climate, or for its protection. Along with the 

 general plan and its greater or less elaboration upon which 

 animals are formed, there are therefore revealed secondary 

 types of formation, which, whether realities or abstractions, 



Ann. & Mag. N. Hist. Ser. 4. Vol. xix. 25 



