78 FOSSIL CIRRIPEDIA. 
the breadth varies with respect to the height; sub-carinated, slightly bowed outwards or 
backwards, and therefore, in the opposite direction to what is usual; but the amount of 
curvature varies much: roof arched, inflected along the lateral edges; basal margin 
protuberant, formed of two curved lines meeting each other at an angle of above 90°. 
The lines of growth on the inflected lateral edges, curve slightly downwards (4), and then 
just perceptibly upwards; thus, no doubt, making the heels or two basal corners slightly 
prominent. Internally, within the lateral edges (having the lines of growth as just described), 
and separated from them by a distinct indentation, there is on each side (4) a narrow ridge, 
widest at about the middle of the upper half of the valve, and marked with longitudinal 
lines of growth; these internal lateral ridges have evidently been (as seen in the section) 
(d) formed during the fillmg up and thickening of the upper, solid, outwardly bowed 
part of the carina, which part, no doubt, projected freely. The lower part of the carina (c) 
is deeply concave. Roemer describes the exterior surface of the shell as marked with 
alternate finer and stronger concentric lines, aad rarely along the edges alone with longi- 
tudinal lines. 
The specimens from the Upper Greensand of Warminster differ from the foreign 
specimens, in being very slightly bowed inwards instead of outwards, and in having a 
more tapering form ; but it is precisely in these two respects, that the four foreign specimens 
seen by me vary to a considerable extent; therefore, at present, the English specimens 
must be ranked under P. Bronniz. 
These valves certainly differ considerably from any other known ones: the slight out- 
ward bowing of the carine from the Hils-conglomerat is their most conspicuous cha- 
racter, and was present in the four specimens seen by me, and I presume, from Roemer’s _ 
description, is general. In recent species, however, the degree of curvature of the carina 
is often variable: in P. syinosus, I have seen some specimens with the upper part of the 
carina even outwardly bent, and others with it straight. The manner in which the upper 
part of the valve has been filled up, having two lateral, inwardly projecting ridges, is unlike 
any other species, and is the main specific character : the carinze of Scalpellum solidulum and 
of the var. cylindraceum of S. maaimum make the nearest approach to this structure. From 
such scanty materials I will not pretend to say to what species this is most closely allied. 
22. PouuicipEs PLANULATUs. ‘Tab. IV, fig. 1]. 
PoLLIcIPES PLANULATUS. J. Morris. Annals of Nat. Hist. vol. xv, 1845, pl. 6, fig. 2. 
— — J. Sowerby. Min. Conch., pl. 647, fig. 2. 
P. tergis subrhombicis, latis, levibus, apice basali laté truncato, latitudine dimidium lon- 
gitudinis marginis occludentis equante ; apice basali truncato angulum rectum cum margine 
scutali formante ; parte superiort marginis scutalis cuspidem latam, rotundatam, leviter 
prominentem formante. 
