6 
GrevillEj on New Diatoms. 
Hab. Barbadoes deposit, Springfield estate; cabinet of L. 
Hardman, Esq. 
Considerably smaller than E. obscurus, and, like that 
species, possessing four processes, but is not otherwise allied 
to it. I place our present little diatom provisionally in 
EupodiscuSy but am doubtful whether that be its true posi- 
tion. The processes, which are situated near the margin, are 
somewhat similar to those of the genus Craspedoporus, having 
the edge next the margin of the disc considerably raised, and 
with a thickened lip. The structure is rather obscure, but 
can be made out to be a faint, uniform, minute, roundish 
cellulation. 
AuLiscus. 
Auliscus Hardmanianus, n. sp., Grev. — Large ; valve 
circular, with two processes ; whole surface more or less 
granulose ; umbilical space four- angled, the angles attenu- 
ated, two of them passing to the base of the obovate ridges 
within which the processes are placed, the other two passing 
into rough transverse lines, terminating in a sort of capitate 
mass of radiating short lines and granules. Diameter '0040"' 
to -0055^^ (Fig. 17.) 
Hab. Monterey deposit ; cabinet of L. Hardman, Esq. 
There is no genus of diatoms in which a greater variety of 
sculpture occurs in proportion to the number of species than 
in Auliscus. The present most remarkable disc, of which I 
have seen a number of examples, is quite unlike any of those 
previously described. The most striking peculiarity is the 
attenuation of the angles of the umbilicus, especially those 
which are intermediate with the processes, which are pro- 
longed into more or less distinct linear channels, ending in 
intra-marginal knobs or rough clusters of short radiating 
lines. These knobs are connected with the ridges surmount- 
ing the processes by a few fine, sometimes obscure lines, 
stretched, as it were, across from one to the other. 
BiDDULPHIA. 
Biddulphia Johnsoniana, n. sp., Grev. — Large; frustules 
oblong, turgid ; valves broadly oval, very minutely scabrous, 
destitute of spines, with large, very shortly produced, 
broadly truncate processes. Diameter of valve '0040"' to 
0055^'. (Figs. 14, 15.) 
Hab. Moron deposit; very rare; C. Johnson, Esq. 
This very rare species has considerable affinity with B. tur- 
