Greville^ on the genus Auliscus. 
47 
tills band and the depressed lateral lobes is sharply defined ; 
the transition from the strong, simple,, somewhat distant 
costse to the network of anastomosing lines being quite 
abrupt. The processes are small, and situated very near to 
the margin. In a frustule from the Cape of Good Hope the 
reticulation is confined to the side lobes of the quatrefoil; 
but in the beautiful Peruvian specimen figured, which belongs 
to my friend Mr. Roper^s cabinet, it extends to the lobes 
connected with the processes, in which, however, the con- 
verging costse preserve their distinctness ; the reticulation 
being produced by sharp lines anastomosing transversely at 
different angles. 
Auliscus mirabilis, n. sp., Grev.— Valve broadly oval, with 
large, definite umbilical space, and marginal border of oblong 
cellules, each cellule penetrated at the base by a short line ; 
area Avithin the border, with the exception of the converging 
costae, more or less filled with a reticulation of anastomosing 
lines. Diameter -0040". (Fig. 11.) 
Hab. Monterey stone ; G. Norman, Esq., G. M. Browne, 
Esq., R. K. G. 
An exquisitely beautiful diatom, and rare as beautiful. It 
was first brought under my notice by Mr. Norman, but his 
specimen had unfortunately sustained some superficial injury. 
That subsequently supplied by Mr. Browne leaves nothing to 
be desired. My own specimen is a fragment. The general 
effect of the ornamentation of the valve is exceedingly rich, 
and resembles a lace pattern; indeed the whole might be 
transferred with little modification to lace manufacture. The 
processes are large, very conspicuous, irregularly circular, 
with a very broad unequal border. The umbilical space de- 
fined, and oval in the direction of the processes. The costse 
which converge to the processes very clear and sharp ; those 
which radiate towards the margin anastomosing, so as to fill 
the lateral space even to the sides of the processes with an 
irregular network. The structure immediately within the 
margin is quite peculiar, being composed of a close row of 
large oblong cellules, penetrated by a small line or spine, 
which reaches past the middle of each cellule. 
Auliscus ovalis, Arn. — Valve oblong-oval; costse all deli- 
cate, several of the lateral ones opposite the umbilicus crested 
near the margin with minute apiculi. Long diameter -0040". 
(Fig. 12.) 
Auliscus ovaliSj Arn. — Ralfs, in Pritch. Inf., 1861, p. 846. 
Hab. Algoa Bay and Peruvian guanos ; Ralfs, F. Kitton, 
Esq., Prof. Walker- Arnott, G. Norman, Esq., R. K. G. 
The form of this species is alone sufficient to distinguish 
