Morphology of some Cretaceous Cirripedes. 369 
Pollicipes jilosus, Withers. 
ye gamigensis, H. B. Geinitz. 
My glaber, ¥. A. Roemer. 
Scalpellum longissimum, Withers. 
“i oppoliense, Leonhard. 
Pollicipes striatus, Darwin. 
iy » var. paucistriatus, H. Woodward. 
Albian : 
Pollicipes unguis, J. de C. Sowerby. 
= imbricatus, Withers. 
Neocomian : 
Pollicipes bronni, F, A. Roemer. 
All the species enumerated above were founded on detached 
valves, and in the case of P. unguis and P. glaber only has 
any number of valves been found in their natural position. 
All the valves have apical umbones. The carina, where 
known, is simple in structure, and by this I mean that it is 
not separated by means of ridges or alteration in direction 
of growth-lines into tectum, parietes, and intraparietes, for 
these parts are not defined, and the valve is strongly convex 
to flatly-arched in transverse section. The scutum, in addi- © 
tion to the apico-basal ridge, has a second ridge, more or Jess 
prominent in the several species, extending from the apex to 
about the middle of the basal margin, and like the Arcoscal- 
pellids has a comparatively wide tergo-lateral portion, which, 
however, varies in width in the several species. The tergum 
is not in any way peculiar, but the valve is usually rounded 
and protuberant along the occludent margin, followed by a 
rather wide furrow extending to the scutal margin. The 
upper latus is rather simple, and forms almost an equilateral 
triangle, with the scutal side a little longer than the tergal, 
but with no elaboration of structure, such as the truncation 
of the basal angles and the growth-lines upturned at the 
sides. Of the lower latera, the carinal latus is the valve 
more frequently found, and this is subtriangular to oblong 
in shape, and is about twice as large as the rostral and 
inframedian latus, which are almost exactly similar in shape 
and size. The rostrum is subtriangular, large, and wide, 
usually with an apico-basal ridge. The peduncular plates 
are large, with a smooth, narrow, inwardly-projecting ledge ; 
on the inner margin of this ledge in the plates belonging to 
P. unguis there is a median elliptical socket, but I have not 
noticed such a feature in the numerous peduncular plates 
that I have seen of P. glaber. 
