101 
Horizon and Localitij. — Goltifuss lias discovered this species in tlie 
Devonian limestone of the Eifel. The specimen collected hy Clarke occurs 
in a yellowish grey, rather friable limestone from the Yass District. 
Genus — YISO ? Risso. 
Niso Daiiwinii, L. G. dc Koninch} 
PI: IV, Fig. 11. 
Shell of moderate size, conical, elongate, fairly regular, composed of 
sixteen to twenty slightly convex spiral whorls, surface smooth, suture linear; 
these whorls are not thick, and not enveloping being connected directly to one 
another by the bases in proportion to the successive growth of the shell. 
This base is almost flat anteriorly and angular towards the outer margin. 
An umbilicus, rather large compared to the transverse diameter of the shell, 
occupies the entire length of the axis. The aperture is sub-rhomboidal in 
shape, and furnished with a small anterior canal, making it slightly projecting ; 
the external margin is sharp, non-sinuate. Spiral angle, 30°. 
Dimensions. — Length, forty ; transverse diameter of the base, twenty ; 
height of the body whorl, eight millimetres. 
Relations and Differences. — I hesitated for some time before deciding 
as to under which genus this species should be placed ; but after much 
searching I have not found any genus the general characters of which agree 
better with those afforded by the several specimens submitted to me than 
Niso. One of the principal causes of my hesitation was that up to the 
present no representative of this genus had been recorded from the formations 
older than the Tertiary. After long and fruitless searches for a Pakeozoic 
species showing some analogy to this form, I have found myself compelled 
to surrender to the evidence and list under Niso a Devonian sj^ecies, which I 
have dedicated to my learned contemporary, Mr. Darwin, who was one of the 
first to explore the coasts of Australia. 
Horizon and Locality. — The three specimens I have had at my dis- 
posal, one of which shows an almost complete longitudinal section, and which 
has been very useful to me in the determining of the generic character, have 
been collected by Mr. Clarke in a black compact limestone in the Yass 
District. 
^{Vetotuha Dairinii. — Mr. E. Etheridge, Jxinr., has proposed a new subgenus — Vdotuha — for the reception 
of this species. Eecords Austr. Mus., 18'JO, I, No. 3, p. 63. — W.S.U.] 
