T. H. Withers—New Chalk Cirripedes. 157 
merge into the sides of the parietes, some distance from their basal 
margins. Surface of tectum and parietes ornamented with very fine 
V-shaped lines of growth. 
Holotype.—A carina (B.M., I. 7235), collected by C. P. Chatwin 
and T. H. Withers. Extreme length 19 mm., greatest breadth 4:5 mm. 
Horizon and Locality.—Cenomanian, upper part of zone of Holaster 
subglobcsus: Oxted Lime Works, Oxted,' Surrey. 
Comparison with other Species.—This species is not unlike Scalpellum 
lineatum, Darwin (1851, p. 35, pl. 1, fig. 12), but in that species the 
sides of the tectum are steeply inclined towards each other, the 
parietes and intraparietes are only separated by a very slight ridge, 
the disposition of the longitudinal ridges is different, and the inter- 
spaces are ornamented with very fine hair-like lines. It may also be 
compared with S. angustum (Dixon), (1850, Geol. Sussex, pl. xxvii, 
fig. 9), and S. hastatum, Darwin (1851, p. 37, pl. 1, fig. 13), both of 
which were founded on single carine. It agrees with S. angustum in 
that the intraparietes only reach about half the length of the valve; 
but disagrees with it in that their bases are not abruptly truncated, 
but merge into the sides of the parietes. Further, the main ornament 
is formed, not by the V-shaped lines of growth, but by the longitudinal 
ridges. From S. hastatum it differs in that the valve is much less 
recurved, has shorter and wider intraparietes, and well-marked 
longitudinal ridges. The holotype of S. hastatum (B.M., 38,462) 
was collected by W. Griffiths in the Grey Chalk (Cenomanian) of 
Dover. Unfortunately, since Darwin figured it the apex has been 
broken off and lost. 
5. ScaLpELLUM LInEATUM, Darwin. 
1851. C. Darwin, Pal. Soc. Monogr. Foss. Lepadide, p. 35, pl. ii, figs. 11, 12. 
1877. H. Woodward, B.M. Cat. Foss. Crustacea, p. 142. 
Darwin had for the description of this species, two carine, ascutum, 
and a tergum, but he assigned the two latter valves to the species 
only with doubt. Taking this into consideration, and since it is best 
that the type should be fixed, I here select the carina figured by 
Darwin (op. cit., pl. 11, fig. 12) as the holotype of S. lineatum. 
_ One of the carine was in the collection of J. Sowerby, and the 
remaining carina and the scutum in the collection of J. Morris. All 
three valves came from the Lower Chalk of Sussex. Unfortunately 
I have been unable to discover what has become of them. 
The tergum (B.M., I. 138,402) came from the Lower Chalk of 
Maidstone, Kent, and was formerly in the Bowerbank Collection. 
6. ScaLPELLUM DISSIMILE, sp. nov. Fig. 14. 
Diagnosis.—General outline of tergum rhomboidal; apex sharply 
pointed; basal angle pomted. Scutal margin straight, shorter than 
the occludent margin, about half the length of the valve. Carinal 
margin divided into two lines forming an obtuse angle, the upper 
portion shorter than the lower, and about the length of the scutal 
margin, the lower portion being about the length of the occludent 
' Exposure noticed, G. E. Dibley, ‘‘ Zonal Features of the Chalk Pits in the 
Rochester, Gravesend, and Croydon Areas’’?: Proc. Geol. Assue., 1900, vol. xvi, 
p. 492. 
