89 
Descriptions of New and Rare Diatoms. Series VI. 
By R. K. Greville, LL.D., F.R.S.E., &c. 
(Communicated by F. C. S. Rop^r, F.L.S., &c.) 
Cymatopleura. 
Cymatopleura angulata, n. sp._, Grev. — Lateral view_, narrow- 
oblong, with elliptic ends ; the transverse undulations at each 
extremity angulated ; margin with a row of minute puncta, 
about 10 in -001". (PI. IX, fig. 1.) 
Hab. Californian guano. 
This species approaches C. elliptic a ; but, in addition to 
being a marine species, appears to be truly distinct. The 
most important character lies in the transverse bars at each 
extremity of the frustule being bent so as to form a distinct 
angle. The outline of the frustule is not strictly elliptical, 
but has more or less straight sides, never, however, panduri- 
form. The length varies from -0035" to '0050" ; breadth in 
the larger examples about -0015''. 
Campylodiscus. 
Campylo discus Broivneanus, n. sp., Grev. — Valve circular ; 
canaliculi slender, numerous (about 48), radiating from an 
ovate or oval blank central space occupying about a fourth 
part of the breadth of the disc. Diameter '0060". (Fig. 2.) 
Hab. Manilla. Obtained from shell-scrapings G. Mans- 
field Browne, Esq. 
Nothing can be more beautiful than the graceful sym- 
metry of this disc ; and, if such an expression be applicable to 
a diatom, it pre-eminently merits the " simplex munditiis^^ 
of Horace. Its nearest ally appears to be my C. Normanianus, 
which was also found in the scrapings of shells {Spo7idyli 
from the West Indies) . The difference is obvious at a single 
glance ; the canaliculi of the latter reaching a linear central 
blank line situated within a linear-oblong depression. 
EUPODISCUS. 
This genus has been much improved by Mr. Ralfs in his 
reference of E. fulvus, crassiis, and Ralfii of Smith to Aciino- 
cyclus of Ehrenberg ; and by the adoption of the genus 
Auliscus of Bailey for Eupodiscus sculptus of Smith. I take 
