28 FOSSIL CIRRIPEDIA. 
different aspect from the ordinary varieties, and do really differ in the sutural edges of the 
alee being crenated, and in the greater narrowness and obliquity of the radii; but these 
points are all commonly variable. I have not seen any large specimens of the variety 
(fig. 2c), plicatus, so as to compare them with the large specimens of the normal form, yet 
I can hardly entertain any doubt, considering their agreement in so many important 
points, that I have rightly treated these forms as mere varieties; it is unfortunate that 
none of the specimens of the var. plicatus seen by me have had opercular valves, as their 
presence would have removed all shadow of doubt. I have given a drawing, enlarged seven 
times, of some very young shells (fig. 2d), adhering in numbers on Pecten Gerardit, which I 
believe belong to the plicated variety of our present species, but which are much too young 
to be identified with certainty. 
Afinities: this is a strongly characterised species, and nearly allied only to the 
following species, B. dolosus. 'The furrows on the scuta in some degree resemble those on 
the recent B. devis, but there is no alliance with that species. It is certain that amongst 
recent species, the chief affinity is with B. Hameri and amaryllis. 
9. Bauanus poxosus. Tab. I, fig. 3a—3d. 
BL. nec parietibus, nec radiis poris perforatis ; basi poris magnis perforata, radiorum 
marginibus superioribus obliquis, levibus ; aciebus suturalibus item levibus ; tergi calcare 
non admodum brevi, } valve latitudine. 
Neither walls nor radii permeated by pores ; basis permeated by large pores ; radii with 
their upper margins oblique and smooth ; sutural edges smooth ; tergum with the spur not 
very short, broad as one third of valve. 
Fossil in Red (Sutton) and Mammaliferous Crag; Mus. S. Wood, Bowerbank, Lyell, J. de C. Sowerby, 
Henslow, &c. Mammaliferous Crag, Postwick, near Norwich, Mus. Lyell. 
This species so closely resembles B. disulcatus, both externally and in all the essential 
characters of the parietes, radii, and basis, that it is quite superfluous to describe 
again these parts. ‘The specific characters are derived from the opercular valves, which 
present well defined distinctions, found by me constant in several specimens of both 
species. B. dolosus, like B. bisulcatus, has quite smooth and deeply plicated varieties, 
often adhering to the same univalve. ‘The ribs on the inner surfaces of the parietes are 
remarkably prominent, as shown in the drawing (fig. 3a) of the inside of the rostrum. I 
think the upper margins of the radii are in this species rather more oblique than in 
B. bisulcatus. 'Vhe sutural edges of the radii are marked by the finest strize, representing 
septa. The sutural edges of the ale are generally distinctly crenated. ‘I'he basis is often 
slightly cup-formed, and very plainly porose (fig. 34): its upper surface is marked by 
