72 FOSSIL CIRRIPEDIA. 



Valve much elongated, sub-rhomboidal ; whole surface rather plainly ribbed longitudinally. 

 A larger rounded ridge, with the surface of the valve depressed on the cariual side of it, 

 runs in a slightly curved line, at about one third of the entire width of the valve from the 

 carinal margin, down to the sharp basal angle. Apex narrow, much produced : occludent 

 margin about equal in length to the scutal margin -. upper and lower carinal margins almost 

 running into each other. Parallel to the occludent margin, the valve is depressed, with a 

 raised plait in the middle of the depression. Except in the more elongated form, and in 

 the character of the ridge running from the apex to the basal angle, this valve is barely 

 distinguishable from the tergum of S. arcuatmi (with its varieties) found in the Chalk 

 Marl and Gault. 



Carina (fig. 4, a). In Mr. Tennant's collection there is a carina from the Chalk of Kent, 

 different from any other seen by me, and which, from being plainly ridged, or rather fur- 

 rowed longitudinally, I provisionally describe here. Valve thin, triangular, moderately 

 tapering ; very slightly bowed inwards ; transversely, very flatly arched ; plainly sub- 

 carinated ; lateral edges narrowly and much inflected ; basal margin rectangularly pointed. 

 A very small portion of the valve projected freely. The internal concavity of the valve is 

 angular, instead of, as usual, being rounded. The whole exterior surface, except close on 

 each side of the central ridge, is longitudinally furrowed. 



17. POLLIOIPES SEMILATUS. Tab. IV, fig. 6. 



P. valvis longitudinaliter et transverse costatis : scutorum marline hasali brevi, recto, 

 cum marline occludente aiicjulum rectum formante : costd, parietali^ tenuissimd ah ajnce ad 

 angulmn prominentem hasi-lateraleni decurrente ; hcec valvam in duas partes incequales 

 dividit, e quibus portio tergo-lateralis latior est. 



Valves longitudinally and transversely ridged : scuta with the basal margin short, 

 straight, forming a rectangle with the occludent margin ; a very narrow wall-sided ridge 

 runs from the apex to the prominent baso-lateral angle, and divides the valve into two 

 unequal portions, of which the tergo-lateral portion is the broadest. 



Chalk Detritus, Charing, Kent. M^is. Harris. 



General Remarks, I know this species only from one minute broken scutum ('IS of an 

 inch in length), with its surface somewhat disintegrated ; but it is certainly distinct from 

 the other species hitherto described. The Chalk detritus at Charing is derived from the 

 upper and lower Chalk and Chalk Marl, 



Scutum ; the surface is marked by narrow, square-edged, longitudinal ridges, placed 

 rather distant from each other ; each zone of growth appears (for the surface is much dis- 

 integrated) to have had a prominent plait or ridge which, consequently, runs in lines 

 transverse to the longitudinal ridges. The upper part of the valve is only moderately 



^ Parietali, i. e. lateribus utrinque perpendicularibus. 



