40 POSSIL CIRRIPEDIA. 



Carina smooth ; parietes extremely narrow, rectangularly inflected ; tectum sub-cari- 

 nated, in a transverse line moderately arched ; basal margin rectangularly pointed. 



Lower Greensand, Maidstone. Mus. J. Morris. 



I know this species only from a single carina, which is chiefly characterised by its 

 simplicity : it is, I think, certainly distinct from all the others. In the sides of the carina 

 being simple, that is in not being divided by a ridge into parietes and intra-parietes, it 

 comes nearest to /S. arcuatum and trilineatum, from the former of which it is readily distin- 

 guished by its smoothness ; and from JS. trilineatum. by the absence of the three ridges. 

 This species possesses some interest, as being the oldest cirripede, which I have ventured 

 to attribute to the genus Scalpellum. Carina moderately tapering, slightly bowed towards 

 the terga ; sub-carinated, but with the central ridge smooth ; transversely moderately 

 arched; basal margin rectangularly pointed; the whole surface is smooth. Parietes 

 extremely narrow, rectangularly inflected, set inwards, not extending down to the basal 

 margin, with the hues of growth almost parallel to the inner edges of the valve. 



11. Scalpellum arcuatum. Tab. I, fig. 7. 



8. valvarum lineis angustis elevatis ah apice radiantibus : carinas tecto transverse leniter 

 arcuato, et parietibus rectaiigule inflexis, leniter concavis, Itsvibus. 



Valves with narrow elevated lines radiating from their apices. Carina with its tectum 

 in a transverse line flatly arched, and with the parietes rectangularly inflected, sUghtly 

 concave, smooth. 



Gault, Folkstone, Mus. Bowerbank, J. Sowerby, Flower, Var. in Grey Chalk, Dover, Mm. Brit. 

 Planer (Chalk-marl) near Hildesheim. Mus. Roeraer, 



1 have ranked this species under Scalpellum instead of PolHcipes, from the somcAvhat 

 greater resemblance of its scuta and carina with the fossil species of Scalpellum, than 

 with any known Pollicipes; though in some respects it appears rather intermediate. 

 This species appears to come nearest to the FoUicipes radiatus of J. de C, Sowerby in 

 ' Geol. Trans.,' vol. iv, 2d Series, PI, XI, fig. 6, but besides that that species comes from 

 the Lower greensand, the lower angle of its tergum is much more pointed; the upper 

 figure of the two there given appears to be something wholly different. From the state of 

 the specimens, I believe that the three following valves, all in Mr. Bowerbank's collection, 

 belonged to the same species. 



General Appearance. Carina, scuta, and terga plainly marked with prominent, very 

 narrow, straight ridges, radiating from their apices; the interspaces between these ridges are 



