POLLICIPES. 75 
closely related to each other, and in a far less degree to P. dorsatus. Some remarks on 
their diagnostic characters will be given under the two following species. All three species 
are remarkable by the peculiar form of their scuta, which have so much resemblance (espe- 
cially in P. rigidus) to the terga of other cirripedes, that until I examined their under 
surfaces I was not sure which valves they were. ‘The conspicuous ridges running obliquely 
downwards from the apices of the scuta and terga, I have little doubt were due to the carina 
and rostrum largely overlapping these valves, and to the presence of large upper latera, so 
that the lower angles of the scuta and terga were closely wedged between these valves. 
19. Poutticipzs FaLLax. Tab. IV, fig. 8. 
P. valvis transverse costatis: scutis, margine basalt non recto, angulum pane rectum 
cum margine occludente formante ; costa, parietibus obliquis, ab apice ad angulum baso-late- 
ralem decurrente: tergis, costd curvatd, parietibus obliquis, ad angulum basalem latum, 
rotundatum, decurrente. 
Valves transversely ridged. Scwta, with the basal margin not straight, forming nearly 
a right angle with the occludent margin; a ridge having sloping sides runs from the apex 
to the baso-lateral angle. erga, with a curved ridge having sloping sides, runs to the 
broad, rounded basal angle. 
Upper Chalk, Norwich. Mus. Fitch. Maéstricht Formation, Balsberg and Kopinge, Scania. Mus. 
Univers. Copenhagen. Oberer Kreidemergel (Upper Chalk), Gehrden in Hanover. Mus. Roemer. 
The specimens which I have seen, consist of three right-hand scuta and one tergum, in 
the possession of Mr. Fitch, from Norwich; of two scuta and two terga collected by M. 
Angelin, in Scania, and forwarded to me by Professor Steenstrup, and of a scutum from 
Hanover, sent to me by Roemer, together with specimens of his P. uncinatus. 
Description. The valves are moderately thick; they are conspicuously marked with 
rather wide prominent ridges, forming the basal edges of each zone of growth; they seem 
in both scuta and terga most strongly developed near the occludent margins. 
Scuta (fig. 8, a) almost triangular, moderately convex ; occludent margin considerably 
arched in the upper part, and bowed towards the terga; basal margin not straight, with 
a short portion close to the rostral angle forming a rectangle with the occludent margin ; 
the remaining portion, if produced, would form a rather larger angle with it; hence the 
baso-lateral portion of the whole valve is somewhat protuberant. The tergo-lateral margin 
is in the upper part slightly hollowed out, and in the lower part almost straight. A very 
slightly curved ridge runs from the apex to the baso-lateral angle, which is broad, rounded, 
and not prominent; the ridge has sloping, not wall-like sides. Internally the structure of 
the upper part closely resembles that of P. rigidus. The furrow on the tergal side is rather 
