SUMMARY OF THE TABLES. 



The following table shows the relative proportions of the different 

 groups included in the fauna and enumerated in the tables preceding : 



In the 



tables. 



Extra 

 limital. 



Brachiopods • 



Pelecypods 



Scaphopods 



Pteropods 



Gastropods 



Cephalopods 



Total 



Deduct extra-limital species 



Total enumerated species from Sandy Hook to Florida and 

 the Rio Grande 



21 



487 



44 



33 



1, 127 



2 



2 



13 

 2 

 3 



59 



1,714 

 79 



79 



1,635 



It may be added that, with but few exceptions, the enumerated extra- 

 limital forms are likely, with further exploration, to be found in our 

 region. 



If all the Nudibranchiata, Heteropoda, and Cephalopoda were enu- 

 merated the total would be at least eighteen hundred forms. 



It is probable that some of the species enumerated in the tables will 

 hereafter prove to be synonymous with other enumerated species. But 

 there is a reasonable prospect of the discovery of deep-water species, 

 new to science or to the region, and of Antillean species which extend 

 to the region of the Florida Keys which are not here enumerated, so 

 that the loss from the above-mentioned cause will probably be more 

 than made up numerically. This being the first attempt to enumerate 

 the Molluscan fauna of the whole region, generalizations may well be 

 deferred. 



176 



