04 FOSSIL CIRRIPEDIA. 



the measurements of tlie Gravcscnd specimen : the scutum is too much broken to be 

 measured, and the breadth only of the basal margin of the carina can be given — it is "25 of 

 an inch ; the terga arc nearly '8 long and fully '4 broad. The upper latus is "27 in height, 

 basal margin '23 in length. Lower latus "2 in height and '26 in breadth. I imagine 

 that the broken scutum belonging to this individual, was fully two thirds of the size of the 

 largest scutum which I have seen, namely, that from Sarstedt, '6 of an inch in length. 



AJJinlties. From the very close affinity of this species to the following one, P. unguis 

 of the Gault, we may safely infer that it had not only a rostrum (of which a specimen found 

 separately has been described), but also a sub-rostrum ; whether it had a sub-carina, as is 

 probable, must remain doubtful. The two faint ridges running from the umbo of each 

 scutum to its basal margin, probably mark the extent to which this valve was overlapped, 

 as in the case of the recent P. niHclIa, by the rostrum and upper latera ; and the ridge on 

 the terga, steep towards the carina, probably shows the extent to which this latter valve 

 reached. It is also probable, as we shall see under the head of P. unguis, that there was 

 only one whorl of valves under the upper latera, and that this included the sub-rostrum : 

 the latera in this lower whorl were probably not very numerous, but large, and of very 

 unequal sizes ; their mutual overlapping no doubt caused the oblique ridges on their 

 exterior surfaces. 



12. POLLICIPES UNGUIS. Tab. IV, fig. 1. 



PoLLiCTPES UNGUIS. J. Sowerby. Geolog. Transac. 2d series, vol. iv, t. xi, fig. 5*. 

 — L^vis. lb. lb. lb. fig. 5 (sed 



non Tab. xvi, fig. 1, — alia species). 



P. scutis incognitis, verisimiliter ut in P. glabra. Margine hasali carina obtuse 

 acuminato, suh-rotundato. Lateribus superioribus] elo?igdtis trianguJaribus, dimidium lon- 

 gitudinis tergorum superantibus. Lateribus anticis inferioribus costd subcentrali instructis. 



Scuta unknown, probably as in P. glaber. Carina, with the basal margin, bluntly 

 pointed, somewhat rounded. 'U2)j)er latera elongated, triangular, exceeding half the 

 length of the terga. Anterior loicer latera, each with a ridge, subcentral. 



Gault ; Folkstone, (common.) Burhara, Eastweare Bay, Maidstone. Mus. Practical Geolog., Bower- 

 bank, J. Sowerby, Brit. Mus., &c. In the Museum of Geolog. Soc. there is a tergum of this species, 

 marked Lower Grcensand, Maidstone, 



General Bemarls. This species comes very close to P. glaber, but can, I think, be 

 safely distinguished from it, even with our present materials. A specimen most unusually 

 perfect is in the Museum of Practical Geology ; it consists of a carina and pair of terga, 

 much mutilated, a rostrum, sub-rostrum, a pair of upper latera, a pair of latera of the 

 lower whorl from the carinal end of the capitulum, and two other latera of this same 



