98 
Horizon and Locality. — A single specimen lias been collected in a 
black compact limestone at Yarradong. 
2. Euomphalus Bigsbyi, L. G. de Koninck. 
PI. IV, Pig. 8. 
Shell of rather large size, spire conical, depressed at base, composed of 
six or seven spiral whorls, very slightly arched, suture little marked, and 
carinate externally. The surface is ornamented with numerous oblique lines 
of growth, leading to the inference of the existence of a rather well-marked 
sinuosity on the exterior edge of the aperture ; this should have been rather 
large and sub-rhomboidal. The umbilicus is large, and enables one to see the 
several whorls of which the spire is composed. The spiral angle is about 110°. 
Dimensions. — Height, about three ; diameter of the base, about six 
centimetres.^ 
Delations and Differences . — This beautiful species, which I have much 
pleasure in dedicating to my venerable and learned colleague. Hr. Bigsby, 
has some resemblance to Trochns oxystomus, Boemer, and Dlatyschisma 
applanatiiin, G. Sandberger. It is distinguished from them l)oth by a lesser 
basal depression in consequence of the greater convexity of the anterior part 
of the body whorl ; it differs also from the last-mentioned in the large size of 
the umbilicus. 
Horizon and Locality . — I am acquainted with only two specimens of 
this sj)ecies. They both occur in the black argillaceous limestone of the Yass 
District. 
Genus — LOXONEMA, J. Dliillips. 
1. Loxonema anglicum, a. d'Orbigny. 
PI. IV, Pig. 9. 
Loxonema rugifera, J. Phillips, 1811, Pal. Poss. Cornwall, p. 101, pi. 38, fig. 188 {n^n- 
idem, Geol. Yorkshire, II, pi. 14, fig. 24). 
,, anglica, A. d’Orbigny, 1850, Proclr. Pal., I, p. 62. 
Shell conical, very elongate, composed of about twenty spiral whorls, 
the growth of which is regular and gradual. Sjhral angle, 12°. Each whorl 
of the spire is ornamented with thirteen or fourteen ridges or elongated 
‘ The specimen I had at my disposal was too imperfect to enable me to give exact measurements. 
