6 FOSSIL CIRRIPEDIA. 
- not heard of any Cirripedé having been as yet discovered in the Upper Oolite, or in the 
Wealden formation. During the deposition of the great Cretaceous. System, the Lepadide 
arrived at their culminant point; there were then three genera, and at least thirty-two 
species, some occurring in every stage of this system. Besides the thirty-two certainly 
‘known cretaceous forms, and several other doubtful ones, I believe that very many more 
will yet be discovered; I infer this from the fact, that in almost every collection lent to 
me for examination, although very small, I have found some new species. I have three 
or four species from the Gault; from five to eight in the Lower Chalk, and from nine to 
twelve species in the Upper Chalk (not including the Faxoe, Scanian, and Maéstricht 
stage) ; and of these nine to twelve species, five have been found by one collector, Mr. Fitch, 
in one locality, namely near Norwich. In Scania M. Angelin has found no less than nine 
or ten species, all belonging to the upper or Maéstricht stage of the Chalk. These fossils, 
judging from the habits of recent species of the same genera, were probably attached to 
fixed, or nearly fixed, objects at the bottom of the sea. Now at the present day, of attached 
Pedunculata (reckoning even Crustacea and Echinide as fixed objects), the whole Mediter- 
ranean and New Zealand can boast each only of three species, in both cases including 
Alepas, which is destitute of calcified valves and therefore not likely to be fossilized ; 
Australia has three species; Madeira has four species, including one with very small and 
imperfectly calcified valves ; the great Phillipine Archipelago, however, has afforded, owing 
to the labours of Mr. Cuming, as many as five species, though including one with horny 
valves, and a Lithotrya which lives embedded on the beach. Therefore since we already 
have nine or ten fossil species from one locality, and from the same stage of the chalk, 
we may admit that the pedunculated Cirripedes arrived during the upper part of ne 
Cretaceous system at their culminant point. 
Although, for this family, the number of species were considerable during the Cretaceous 
period, the individuals were mostly rare. I infer this from the small number of specimens 
in all collections ; for instance, Mr. Fitch, who has assiduously collected for twenty years 
in the chalk near Norwich, possesses in his entire collection only nine keel-valves of Sca/- 
pellum maximum, and six of 8. fossula ; he has two Scuta (and with regard to these valves, 
it must be remembered, that each individual had two) of Pollicipes striatus, two of 
P. fallax, and four of P. Angelini. This occasional want of a relation, within the same 
region, between the number of the species in any given genus, and of the individuals 
appertaining to such species, is a singular fact, and has been strongly insisted on by Dr. 
Hooker, in regard to the Coniferous trees of the southern hemisphere: one would 
naturally have expected, that where circumstances favoured the existence of numerous 
species of a genus, they would likewise have favoured the multiplication of the indi- 
viduals in all or most of such species; but this, as we here see, has not always been 
the case. 
In the Eocene, Miocene, and Pliocene Tertiary deposits, I know only of two species of 
Scalpellum, and two of Pollicipes, with indications of two or three other species, all distinct 

