342 Dr. H. Woodward — Cirripedcs from Trimmingham Chalk, 



valves which I propose to treat as belonging to the same form of 

 Cirripede. (See Figs. 5-10.) 



Carina (Figs. 5-7). — Nearly straight, semi-conical, feebly swollen 

 in the lower part of its length ; the basal border slightly excavated ; 

 the interior deeply concave, one sees that a considerable part of 

 the summit projected freely, as does the apex of the carina and that 

 of the rostrum also in the living PolUcipes mitella (see ante, p. 340, 

 Fig. B, c, r; and Darwin's " LepadidfB," Kay Society, 1851, 

 pi. vii, fig. 3). Lines of growth, more strongly marked near the 

 lower border, encircle the carlnal valve from the base to the summit. 



Suh-carina. — This valve differs but little in form from the sub- 

 rostrum, but M. Bosquet believes it to be the sub-carina on account 

 of its dimensions, and because he thinks its form corresponds with 

 that of the carina ; it is much more slender than the latter, and its 

 summit is slightly inflected, and for about one-third of its length it 

 probably projected freely. 



Figs 



11-13. — Three terga of Braehylepas {FoUieipes) fallax, 

 X 2 uat. size. From the Chalk of Triiumingham. 



Darwin, sp. 



Bostrum (Figs. 8, 9). — Smaller than the carina, semicircular at the 

 base, and more triangular in form, the apex more or less inflected, 

 and its basal portion nearly flat, with the feeblest indication of 

 a median longitudinal keel, the transverse lines of growth are 

 clearly marked ; deeply concave within and projecting freely at its 

 upper part. 



Suh-rosirnm (Fig. 10). — This is much shorter and proportionally 

 broader than the rostrum ; it is slightly carinated, and the surface 

 shows some very feeble longitudinal grooves, the basal border is 

 verj' slightly excavated, and the upper part projected freely. 



Description of scutum and tergum.^ — "The valves are moderately 

 thick ; they are conspicuously marked with rather wide prominent 

 ridges, forming the basal edges of each zone of growth ; they seem 

 in both scuta and terga most strongly developed near the occludent 

 margins. (See Figs. 11-18.) 



' After Darwin's monograph, p. 75. 



