Greville^ on the genus Auliscus, 
45 
R. K. G. Bolivian guano and Monterey stone^ G. M. Browne, 
Esq. Bass^ Straits, C. Johnson, Esq. ; New Zealand, G. M. 
Browne, Esq. ; Harvey Bay, Queensland, New Caledonia, 
and Woodlark Island, in dredgings communicated by Dr. 
Koberts ; B. K. G. ; Brodick Bay, Island of Arran, E. K. G. 
Having already referred to this species under the previous 
article, I am not called upon to enter into many additional 
details. The most essential character, perhaps, resides in 
the apiculi, wdiich are sometimes so numerous as to render 
the whole area of the depressions quite rough, surrounding 
even the umbilical space ; wdiile, in other cases, they are few 
and scattered, or occur only on the ridge or outer curve 
of the depressions. Typical specimens seem to exhibit two 
or three minute apiculi or tubercles on the costse, following 
exactly the curve of the depression. In the Arran example 
(fig. 4), which much resembles A. sculpUis, there are very 
few apiculi, and they are so situated ; but, in addition to 
this character, the radiating costse of the depressions are 
continued to the margin. The range of size is extraordinary. 
Those from Ichaboe guano, obtained, I believe, only by Mr. 
G. M. Browne and myself, are so far beyond the average 
dimensions, that it is probable they may be sporangial. I 
am not disposed to place any reliance on the presence or 
absence of anastomosing lines among the costse of the de- 
pressions, as they appear to be sometimes nearly, if not quite 
absent. A few may be occasionally perceived in the neigh- 
bourhood of the umbilical space ; while they are sometimes 
so numerous as almost to amount to reticulation, only being 
too irregular to deserve that name. Not unfrequently 
the depressions, instead of forming semicircular lobes, unite 
with the umbilical space, and resemble an oblong bar 
stretched across the valve, scarcely dilated at each end, and 
rough with apiculi. The depressions are considerably more 
shallow than in the preceding species, or, in other words, 
the undulation of the surface is less prominent. No cha- 
racter of any value can be obtained from the marginal 
costae, which, although generally distant, are sometimes 
double the ordinary number. A very fine valve, kindly com - 
municated by Mr. Bright well, and obtained from sponge 
sand, without any specified locality, and named A. sculptus, 
I take to be the present species. There are, indeed, no 
apiculi, but the costse within the depressions pass into a 
perfect anastomosing network, unlike anything I have seen 
in A. sculptus ; and the marginal costse are very numerous. 
Auliscus elegans, n. sp., Grev. — Valve circular, with a 
small, round umbilical space ; radiating costse proceeding to 
