Morphology of some Cretaceous Cirripedes. 377 
rather steeper on the carinal side, and a little nearer to the 
carinal than to the scutal angle. The surface of the valve 
slopes fairly evenly each side of the ridge. The upper and 
lower carinal margins are straight, the upper carinal margin 
being about one-third the length of the lower, and forming 
with it an angle situated about one-fifth the length of the 
valve from the apex; occludent margin slightly convex, a 
narrow rim along this margin being somewhat protuberant 
and divided off from the rest of the valve by a parallel 
depression which is wider towards the scutal margin; scutal 
margin almost straight, slightly produced below the pro- 
tuberant occludent rim, and forming with the occludent 
margin an angle situated nearly two-thirds the distance 
from the apex. On the inner surface the inner occludent 
edge is rather narrower than the upper carinal edge, but 
both edges are narrow and are marked with growth-lines 
indicating that only a very small part of the valve freely 
projected, 
Remarks.—This species is characterised not only by its 
unusually wide and outwardly bowed carina, but by the way 
in which the inner infilled apical part of that valve is pro- 
duced into the two lateral and inwardly projecting ridges. 
Of the specimens from Essen one only (I. 15449) is not 
outwardly bent, but this is practically straight and cannot 
be said to be bowed inwards. It would seem therefore to be 
a fairly constant character for the carina to be bowed 
outwards, although in some recent species this feature is 
often variable. I have not seen a carina of the Gault 
P.unguis that is bowed outwards, but of the Chalk P. glaber 
one does rarely come across carine that are strongly bowed 
outwards. The scutum of P. bronni is peculiar in the strong 
inflection of the tergo-lateral portion, and the tergum in the 
shortness of the upper carinal margin. 
I have not seen any examples of the carina from the 
Warminster beds referred by Darwin to this species, but, 
since the outward bending of the carina seems to be such a 
constant character of P. bronni, 1 am not at all sure that 
the Warminster form which is bowed inwards—and what is 
more important has a more tapering form—can be the same 
species. 
PHYLOGENETIC PosITION. 
The capitulum of Cretiscalpellum is remarkably erect and 
Scalpellum-like, and quite unlike the short and rather squat 
multi-valved capitulum of Pollicipes (Miiclla). In the 
general build of the capitulum, and the relative position of 
Ann. & Mag. N. Hist. Ser. 9. Vol. x. 25 
