60 FOSSIL CIRRIPEDIA. 
[B.| Scuta, costd, nonnumquam subobsoleté, ab apice ad centrum marginis basilis 
decurrente." 
110. Potticipes carinatus. Tab. ITI, fig. 9. 
PoLuiciPEs CARINATUS. Phillippi. Enum. Mollusc. Siciliz, 1836, Tab. xii, figs. 26, 28. 
P. scutis crassiusculis ad formam trianguli equianguli accedentibus ; margine occludente externé costd 
humuli firmato ; costd firmd ab apice ad centrum marginis basulis decurrente ; margine basali recto; angulo 
baso-laterali truncato, brevi ; segymentum tergo-laterale ex lineis incrementi reflexis formatum, deest. Carind 
eaterné valde carinatd cum sulco laterali ad utrumque latus. 
Scuta moderately thick, in shape nearly an equilateral triangle ; occludent margin exteriorly strengthened 
by a slight ridge; a strong ridge runs from the apex to the middle of the basal margin; basal margin 
straight ; baso-lateral angle truncated, short: the tergo-lateral portion, formed by upturned lines of growth, 
is absent. Carina, exteriorly, strongly carinated, with a lateral furrow on each side. 
Tertiary; Messina, Sicily. 
I owe to the great kindness of Dr. Phillippi an examination of an authentic series of specimens. Valves 
rather thick, with the lines of growth plain, and with a few fine strize radiating from their apices: these 
striae are sometimes so conspicuous, that I have doubted whether the species ought not to have been 
placed in the next section. 
Scuta (fig. 9, d, e) ; triangular, with the apex slightly bowed over towards the terga ; moderately convex ; 
occludent margin slightly arched, about equal in length to the slightly hollowed-out tergo-lateral margin ; 
basal margin nearly straight, though formed by two lines meeting each other, sometimes with the 
rostral half not descending so low as the other half; this margin forms equal angles with the other two 
margins. The baso-lateral angle is obliquely truncated: there is no tergo-lateral slip formed by upturned 
zones of growth. The occludent margin is exteriorly strengthened in a manner only just perceptible 
by a flattened rim. A strong, conspicuous, and prominent ridge runs, in a slightly curved course, from 
the apex to a point in the basal margin, rather nearer to the rostral than to the baso-lateral angle ; 
this point just perceptibly projects beyond the rest of the basal margin: the ridge is either moderately 
sharp, or broad and flat-topped ; it marks the line of chief curvature of the valve. Internally (e), the pit for 
the adductor muscle is not very strongly developed, and to a different degree in different specimens: the 
internal surface of the centre of the apex is prominent ; on its tergal side there is no furrow, but a rect- 
angular indentation formed by a remarkably wide, flat, smooth ledge, which runs down, narrowing, to the 
baso-lateral angle ; hence the scuta along the whole of this side, especially in the upper part, must have widely 
overlapped the terga, in a manner and to a degree I have not seen equalled in any other Pollicipes; but the 
two valves cannot be said to have been articulated together. The internal occludent edge widens a little in 
the upper part, and is here divided by an oblique line, with the lines of growth apparently discontinuous on 
opposite sides of it, into two portions, of which the inner portion is slightly more prominent than the outer. 
I have already alluded to the fact, that in some specimens the scuta are strongly ribbed longitudinally, 
-in some very faintly striated, and in others smooth. 
Terga (fig. 9, a, 6) ; sub-rhomboidal, elongated, exteriorly convex, internally very slightly concave: upper 
part very thick and solid, with a considerable portion freely projecting, and internally marked by lines of 
growth : along the middle of the portion thus marked, there isa slight longitudinal depression, which is worth - 
remarking, inasmuch as (judging from a conspicuous and analogous character in certain recent species of 
Lithotrya) it was probably caused by the internal central crest of the upper part of the carina. Occludent 
margin slightly convex, very little shorter than the scntal margin ; upper and lower carinal margins nearly 
equal in length; they meet each other at a very open angle: upper carinal and occludent margins meet each 
other at an angle of only a little above 50°. A prominent, strongly marked ridge, (with both sides of the 
