XXII 



Genus Scalpclluni^ almost as old as Pollicipes, but not quite, not being represented in the 

 Lower Oolite ; it is represented by numerous species, however, in secondary and 

 tertiary strata. Number of recent species very large, at least 125 being at present 

 known ; distributed through all the seas and oceans of the world. Bathymetrical 

 distribution a very wide one : the different species range from the coast down to 

 the greatest depths inhabited by Cirripedes (± 5000 m.). 



Genus Verruca, The oldest known species dates back to secondary times. A species that is 

 still existing ranges from the Coralline Crag through different tertiary deposits. 

 Number of recent species considerable, 36 being at present known. Found in all 

 the seas of the world, being more numerous, however, in deeper water. Bathy- 

 metrical distribution' a wide one, ranging from the coast down to 3400 m., not 

 quite so wide-, however, as was found for the genus Scalpclluni. 



Genus Ba/anus. The earlier species appeared during the deposition of the Eocene beds, 110 

 secondary species of this genus being known. Species very numerous in tertiary 

 formations. Number of living species very considerable : more than 70 being at 

 present known. Distribution all over the world's surface, numerous species inhabiting 

 tidal rocks, coastal and shallow waters. Some go down into a more considerable 

 depth, a few only are true deep-sea species. The greatest depth inhabited by a 

 species of Balamis was found to be 564 m. 



To close this introduction, the following list enumerates the Stations where species 

 of Cirripedia were collected, indicating the place of the Station, its depth and the 

 character of the bottom, and mentioning the name of the species that were collected. 

 Places between the stations where Cirripedia were collected during shore-exploration are 

 mentioned in the list. 



1 The place of each Station is only roughly indicated. The exact position of the Stations is given with the descriptions of the species. 



