50 FOSSIL CIRRIPEDIA. 
have a different appearance from their homologues in any recent species: they are 
trigonal, with their basal margin rounded and one end produced, to which end a narrow 
well defined ridge runs obliquely from the apex of the valve. 
The peduncle is known only in P. concinnus ; in this species it is covered with minute 
quadrangular calcified scales. 
+. Scuta, aut levia aut lineis tenuibus incrementi solim notata. 
A. Scuta, costa ab apice ad centrum marginis basalis non decurrente. 
1. Ponnicrpes Concinnus. Plate III, fig. 1. 
PoLLicIPpEs conctinNus. J. Morris. Annals of Nat. Hist., vol. xv, 1845, p. 30, 
pl. vi, fig. 1, et Mineral Conch., pl. 647, fig. 1. 
P. scutis pane quadratis, margine basali prope rostrum subconcavo, segmento tergo- 
laterali, é lineis incrementi ut videtur reflexis formato, lato, rotundato et prominente : tergus 
latis, pene quadratis: carine margine basali, ut videtur acuto. | 
Scuta, almost square, with the basal margin near the rostrum a little hollowed out ; 
tergo-lateral slip, apparently formed by upturned lines of growth, broad, rounded, and 
protuberant. Zerga broad, almost square. Carina, with the basal margin apparently 
pointed. 
Oxford Clay, Middle Oolite, attached to an Ammonite. Mus. Pearce. 
Although to my great regret the state of Mr. Pearce’s health has prevented him 
allowing me to examine the specimens in his possession, yet I have thought it advisable to 
commence the genus with this species, as it is in a far better state of preservation than any 
other specimen hitherto discovered. We gain bya single glance the knowledge that at so 
remote a period as the Middle oolite a true Pollicipes existed. In no other instance that I 
have heard of, has the peduncle been perfectly preserved. Mr. Morris first named and briefly 
described this interesting species ; subsequently Mr. James Sowerby has given enlarged 
drawings (without any description) of it in the ‘ Mineral Conchology ;’ and it is from these 
figures that I have drawn up my specific description, which, from this cause, is necessarily 
imperfect. The figures in this volume are copied from those in the ‘ Mineral Conchology,’ 
which I may remark have evidently been executed with great care, and Mr. Sowerby’s 
accuracy of observation is universally well known. ‘The peduncle is several times longer 
than the capitulum: Mr. Morris describes the scales on the peduncle as being small, closely 
pressed together, somewhat quadrate in form, and each regularly marked by a transverse 
carinated ridge; this latter character I do not understand. ‘The rostrum is not clearly 
figured by Mr. Sowerby, but I believe that I can see evidence of its existence. From 
these materials it would appear that the P. concinnus is more nearly related to the recent 
P. cornucopia, and its two nearest congeners, than to the other species of the genus. 
