GrevillEj on New Species of Campylo discus. 31 
striation of the centre is somewhat obscure. The lines are 
fine, and rather close, and the moniliform character appears 
in certain lights to be produced by minute, subremote puncta, 
planted, as it were, on the striae. 
C.notatus, n. sp., Grev. — Valve nearly circular; canaliculi 
numerous, about 12 in -001", in length more than half the 
radius central area an oval space, traversed vertically by a 
very thick bar, which is dilated and crescent- shaped at each 
end. Diameter -0018" to '0023'. Fig. 4. 
In cleanings of Spondyli ; George Norman, Esq. 
A very singular species, distinguished at once by the 
marking of the centre, w^hich Mr. Norman aptly compares 
to the figure of a dumb-bell. 
C. ambiguuSj n. sp., Grev. — Valve nearly circular; cana- 
liculi distant (about 22), reaching nearly to the centre, 
partially interrupted at about the middle of the radius; the 
centre furnished with an oblong depression, within which 
is a short, linear- elliptical median blank line. Marginal 
striae 11 in -001". Diameter about -0028". Fig. 5. 
In washings of small algse from Jamaica; H. K. G. On 
Spondyli (fragment) in a slide communicated by Mr. George 
Norman. 
An exceedingly curious species, presenting an aspect at 
once suggestive of an affinity with Surirella fastuosa. This is 
chiefly owing to the small number of the canaliculi, and to the 
singular interruption in their continuity. They are firm and 
strong at their internal extremity ; and at a point about the 
middle of the radius, deviate slightly from the straight line, 
as if they were going to fork or become inflated, as in 
Surirella fastuosa. The margin, however, is that of a Cam- 
py lodiscus, and the valve is very considerably curved. It is 
a highly graceful species. 
C. diplostictus, n. sp., Norman. — Valve nearly circular ; 
cellules linear-oblong, in pairs, forming long radiating lines, 
which at the margin alternate with one or two short ones. 
Diameter -0055" to -0070". Fig. 6. 
From Ascidians, Shark Bay, on the west coast of Australia ; 
Dr. Macdonald ; kindlv communicated by George Norman, 
Esq. 
It will be immediately perceived that while this magni- 
ficent species approximates to C. cribrosus, it is strikingly 
distinct. In the species just mentioned, the cellules are, as 
described by Professor Smith, irregularly circular ; in Mr. 
Norman^ s diatom they are regularly narrow oblong, so 
regular, in fact, as to form pairs throughout the whole length 
of the radiating lines; thf^n. instead of the cellules being 
