93 
67a5s— GASTEROPODA. 
Genus — DENTALIUM, Linn<Bus. 
1. Dentalium antiquum, Goldfuss. 
DeutaUum antiqmini ? Goldfuss, 1844, Petref. Germ., Ill, p. 2, pi. 163, fig. 2. 
Among the specimens that have been entrusted to me by Mr. Clarke I 
have come across two pieces of blackish limestone, of which the first shows 
on one surface the marks of a transverse section and the second that of a 
longitudinal section of Dentalium, characterised distinctly by the entire 
absence of internal septa and siphuncle. As the outline of these sections 
corresponds exactly with that which Goldfuss has named Dentalium antiquum, 
I am led to believe that the Australian specimens belong to the same species. 
The existence of a third specimen freer from the matrix strengthens me in 
this opinion. In fact the surface is covered with transverse lines of growth 
in all respects similar to those ornamenting the specimens collected in the 
Eifel. 
Dimensions. — Length, fifty-five millimetres ; diameter of the anterior 
opening, six millimetres. 
Dorizon and Localities. of the two specimens examined comes 
from the Yass District and the other from Yarradong. This last specimen 
contains, as well as the Dentalium, several specimens of Sqnrifer Yassensis, 
and there is no doubt as to its Devonian age. 
2. Dentalium tenuissimum, L. G. de Koninek. 
PI. IV, Pig. '3. 
Shell in the form of a very elongated cone, straight, almost cylindrical, 
cross section circular, shell very thin ; surface smooth. 
Dimensions. — As I know only an incomplete specimen of this species, 
it is impossible for me to give its exact dimensions. This specimen is thirty- 
five millimetres long ; the diameter of the anterior end is five millimetres, 
and that of the opposite broken end four millimetres. 
Relations and Differences.' — -In its straight form tliis species resembles 
D. annulatum, G. Sandberger, and qmiscum, Munster. It is distinguished 
from the first by the thinness of its shell and by the total absence of orna- 
mentation from its surface, and from the second by its relatively less conical 
and more elongate shape. 
