30 
2. Pterinea ptjmila, L. G. de Koninch. 
PI. I, fig. 4. 
This little shell, -which seems to he siihequivalve, is obliquely suhoval, 
a little gibbous, longer than broad ; the posterior side is feebly sinuated, and 
forms a very obtuse angle with the cardinal margin. The anterior side is 
almost straight ; the anterior ear small, a little lobed ; the posterior flattened 
and fairly large. The outer surface is covered with well marked concentric 
growth lines, somewhat unequal ; they are sometimes broken up by small 
slightly elongated inflations, longitudinal in direction. 
Dimensions. — Length, ten millimetres; width, seven to eight milli- 
metres. 
Delations and Differences. — The general shape of this shell resembles 
that of Dterinea suhlcevis, McCoy ; but as well as being smaller, it is more 
elongate and much more strongly striated than this species. 
Horizon and Locality. — Though the specimen I have before me 
contains a large number of individuals, almost all are represented by the 
right valve. They are contained in a very compact olive -coloured calcareous 
shale (mudstone) from Yarralumla. As they are associated with Atrypa ? 
hemispherica, it is evident that they come from the same geological horizon 
as the preceding species. 
C/css— GASTEROPODA. 
Order— mOSOVRAmmkTA. 
Genus — EUOMPHALUS, Sowerhy. 
1. Euomphalus soLARioiDEs, L. G. dc Koninch'. 
. PL I, fig. 5. 
Bhell discoid, spire slightly depressed below the level of the last whorl. 
The whorls of the spire are five or six in number, enveloping very slightly 
and tuiming almost in the same plane ; the section is transversly suboval, 
slightly angular towards the external margin. The suture is well marked by 
a spiral furrow ; the surface is quite smooth on the side of the umbilicus, 
which is very large and shallow ; on the other surface it is ornamented with 
a large number of transverse tubercles, little noticeable on the last whorl of 
the spire, but very distinct on the others, and especially so on the second. 
