68 FOSSIL CIRRIPEDIA. 
on the lower latera,—this species comes much nearer to P. mitel/a than to any other recent 
species ; I believe, however, that it must have had much fewer valves.t From the growth 
113. Poniicipes vaLipus. Tab. IV, fig. 2. 
PoLLicipEs vALIDUS. Steenstrup. Kroyer's Tidsskrift, 1839, pl. v, figs. 28—32. 
P. scutis crassissimis, angustis ; margine occludente externé costd rotundatd forti firmato ; intus promi- 
nentid rostrali infra marginem rectum basalem dependente; costd ab apice ad marginem basalem propius 
ad rostralem quam ad basi-lateralem angulum accedente. Carind levissimd, transverse semicylindricd ; parte 
superiort liberé prominente, interne aut pland aut cristd centrali instructd. 
Seuta, extraordinarily thick, narrow ; occludent margin exteriorly strengthened by a rounded, strong 
ridge; internally, at the rostral angle, a blunt tooth depends beneath the straight basal margin: the ridge 
running from the apex to the basal margin is nearer to the rostral than to the baso-lateral angle. Carina 
very smooth, transversely semi-cylindrical ; upper freely projecting portion internally, either solid and flat, 
or with a central prominent crest. 
Scania, Sweden. Mus. Univers. Copenhagen. Petersberg, near Maéstricht. 
My materials consist of several scuta and carinz, sent me by Professor Steenstrup as belonging to the 
same species, which is likewise the opinion of that able collector, M. Angelin, who has found this species in 
various localities in Scania. A very fine carina, from near Maestricht, has been sent to me by Krantz, of Bonn. 
Valves, remarkably thick, massive, and strong. Scuta (fig. 2, e, f, g, nat. size) elongated, being twice 
as long as broad; slightly convex ; whole upper part bent towards the terga; surface, in some specimens, 
with traces of longitudinal striz. Basal margin formed obscurely (partly owing to the rubbed condition of 
all the specimens), by two lines meeting each other at a very open angle. Occludent margin much arched, 
forming with the basal margin, taken as a whole, an angle of about 60°: tergo-lateral margin nearly straight, 
forming a rectangle with the adjoining portion of the basal margin. That part of the valve formed by the 
upturned zones of growth is narrow, being, in the widest part, barely half the width of the other part of the 
valve. The occludent margin is strengthened by a rounded, strong, projecting ledge, running along its entire 
length; the basal end of this ledge, and consequently the lines of growth crossing it, are oblique, and 
slightly upturned. A slight ridge, or angle, runs from the apex to the baso-lateral angle, and a second, still 
slighter ridge, to a point in the basal margin rather nearer to the rostral than to the baso-lateral angle. 
Close to the rostral angle, the internal lamina of the shell is produced downwards into a strong, blunt tooth, 
which (when not too much worn) can be seen from the external side, depending beneath the basal margin : 
this is the most singular character of the species. The internal occludent edge is broad (and of nearly 
the same breadth throughout the whole upper part of the valve), flat, and marked by lines of growth: this 
striated internal edge is separated from the smooth, depending, rostral tooth, by a very oblique line. The 
pit for the adductor muscle is very deep: above this pit there does not appear to have been any furrow on 
either margin, or any marked central prominence. 
Carina (fig. 2, a, 6, ce, d, nat. size), broad, extremely solid, much bowed inwards; the upper part, even 
more than half the valve in length, must have freely projected; exterior surface transversely semi-cylindrical, 
or rather steeper than a semi-cylinder, but not at all carinated: basal margin not at all protuberant ; lateral 
angles, or heels, just perceptibly projecting below the central part of the basal margin: in the Maestricht 
specimen it appears that there was a very slight furrow near each exterior lateral margin, making them just 
perceptibly protuberant. The internal, smooth, corium-covered surface is concave, forming almost an equi- 
lateral triangle (4): above this, the inner freely projecting portion is either filled up flat, or forms a central 
prominent crest (d). 
Affinities. We shall immediately see that this species appears to be most closely allied to P. gracilis, 
of Roemer: it is also allied to P. dorsatus, by the strength of the valves, by the occludent margin of the 
