54 FOSSIL CIRRIPEDIA. 



5. PoLLiciPES POLiTus. Tab. Ill, fig. 4. 



P. scutis fere rhombicis, lavissimis ; marline basali aim margine ocdudente angiilum 

 recto majorem formante ; margine ocdudente projecturd parietali,^ lineari, minutd instrticto ; 

 internd apicis superficie concavd. 



Scuta, almost rhomboidal, excessively smooth, basal margin forming above a right angle 

 with the occludent margin, which latter is exteriorly furnished with a linear, minute, wall- 

 sided ledge ; apex with its internal surface concave. 



Bins. Bowerbank. Locality and formation unknown ; from the state of another specimen fastened on 

 the same board, I think probably from the Gault ; the colour of the substance in the cracks of the valve 

 countenances this same opinion. 



I have been unwilling to fix a specific name to a single, much broken scutum ; but as 

 even in its present state it can be clearly seen to be distinct, and as this is the typical valve 

 in this genus, I have felt myself compelled to do so. 



Scutum sub-rhomboidal, approaching to oval in outline : rather thin ; surface excessively 

 smooth ; slightly convex, but with a narrow portion along the occludent margin, somewhat 

 inflected : exteriorly close to this same margin, or rather almost forming it, {b) there is an 

 extremely narrow, sharp, wall-sided, projecting ledge. The occludent margin is slightly 

 arched, and forms, with the basal margin, an angle considerably above a right angle, so 

 that the whole baso-lateral corner of the valve is much produced : the lower part of the 

 tergo-lateral margin is at right angles to the basal margin. Baso-lateral angle smoothly 

 rounded, with no trace of a ridge running from it to the apex, though this is the 

 line of chief flexure of the valve. Internally, the valve has been much injured ; the de- 



protuberant ; surface smooth, but near the pointed, slightly curled apex, it is marked by fine radiating 

 lines ; carinal margin regularly curved from the apex to the basal angle, which latter is not very sharp. 

 A curved ridge (formed by the surface of the shell being lower on the carinal than on the other side) 

 connects the upper and basal apices, running almost parallel to the carinal margin, and at about one-fourth 

 of the entire width of the valve from the latter margin. Occludent margin shorter than the scutal ; 

 rounded, protuberant, with a depression parallel to it; the scutal margin, corresponding with this depression, 

 being slightly hollowed out ; a small portion of the apex projects freely. Internally, and nearer to the 

 occludent than to the carinal margin, there are three or four short parallel longitudinal ridges or crests, as 

 described in Scalpellum arcuatum. 



Carina (Tab. Ill, fig. 3, a) moderately bowed inwards, widening gradually from the apex to the 

 basal margin, which is rounded and protuberant, and with a trace of an angular bend in the middle ; 

 exteriorly the surface presents just a trace of being sub-carinated ; roof convex ; the upper part of the 

 valve projects freely. 



Rostrum : Koch and Dunker figure valves, which, from their general appearance, breadth, and appa- 

 rently large proportional upper, freely-projecting portion, I have little doubt have been rightly considered 

 by them as rostra ; they are, however, longitudinally plicated or striated to a greater extent than the 

 other valves. 



^ Parietali, i. e. lateribus utrinque perpendicularibus. 



