6 



INTRODUCTION. 



I do not believe, if all the specimens of Balani hitherto found in the several tertiary 

 formations, from the Eocene to the Glacial deposits, throughout Europe, were collected 

 together, they would amount to twenty species. I have myself seen, in a recognisable 

 state, only twelve fossil species, of which five are extinct or not found in any neighbouring 

 sea : I think it probable that three other recent species, viz., B. tulipiformis, perforatus, 

 and amphitrite, may occur in the Mediterranean formations : and this would make fifteen 

 species. Therefore, in the above estimate of twenty species, five are allowed for species 

 existing in European collections, but not hitherto seen by me ; and this, I believe, is a very 

 full allowance. Consequently, even on the supposition that the five species just admitted 

 as possibly existing in cabinets, and that the other five extinct species, which I have seen 

 and examined, have all been previously named by other authors, a supposition excessively 

 improbable, even then there would be fifteen superfluous names in Bronn. 



The following short table shows how the Balanidae and Verrucidae were represented in 

 Great Britain, throughout the several Tertiary Stages. It includes all the sixteen species 

 described in the following pages, with the exception of one, the cretaceous Verruca prisca, 

 which is the only member of either family hitherto found in any Secondary deposit. 



Name. 



Living species, 



but found fossil 



in some tertiary 



deposits. 



Mammaliferous 



crag, and glacial 



deposits. 



03 

 t-t 



u 



P5 



03° 

 U 



u 

 <D 

 a 



"o3 

 Eh 

 O 



O 



c 



u 

 o 



Balanus tintinnabulum 

 calceolus 

 spongicola 

 concavus 

 porcatus . 

 crenatus . 

 Hameri . 

 bisulcatus 

 dolosus . 

 inclusus . 

 unguiformis 



Acasta undulata . 



Pyrgoma anglicum 



Coronula barbara . 



Verruca Strbmia . 







* 

 * 

 * 

 * 

 * 



* 



* 

 * 





* 



* 

 * 



* 

 * 



* 



* 

 * 

 * 

 * 



* 



* 



* 

 * 



* 



* 

 * 



* 



* 



* 



* 



i 



* 



Total 15, receut and extinct, 

 found fossil in Great Britain, 

 in some tertiary deposit 



9 



5 



8 



9 



1 



