™, 
194 MONOGRAPH OF BRITISH LAND AND FRESHWATER MOLLUSCA. 
FOSSIL SPECIES. 
GENUS PYRAMIDULA Fitzinger. 
SuB-GENUS Charopa Albers. 
Pyramidula omphala (Edwards). 
Ilelix striatella 8. V. Wood, Geol. Journ., i., p. 118 (not Anthony). 
— omphalus Edwards, Mon. Eoe. Moll., 1852, p. 65, pl. 10, ff. 6 a-e. 
Patula omphalus Sandberger, Vorwelt, 1872, p. 289, pl. 
SHELL somewhat discoidal, with a slightly exserted SPIRE of about four (or 
according to the figure, between five and six) rounded or bluntly convex WHORLS, 
but which in two casts of fully-grown individuals in Mr. Edwards’ collection pre- 
sented a subcarinate periphery ; and shallow rounded sulci in the lines of growth, 
which are oblique, undulating, and rounded ; the margins of the depressed semi- 
lunar APERTURE are simple and unreflected ; and the UMBILICUS perspectively 
open. Diam. 7 mill. ; alt. 3 mill. 
9 >») 
Fic, 244. Fic. 245. Fic. 246. 
Pyramidula omphala (Edwards). 
Fic. 244.—Natural size. Fic. 245.—Upper, frontal, and basal aspect, X 2. Fic. 246.—Sculpture 
of body-whorl, x 4 (after Edwards). 
Mr. Searles V. Wood formerly regarded this species as identical with 
the Pyramidula striatella of Mr. J. G. Anthony, but our species has a 
less elevated spire, deeper sulci, and other points of difference. 
Prof. Sandberger considers this species to have its closest affinity to 
Pyramidula comma of Gray, a native of New Zealand, and a member of 
the sub-genus Charopa, an ancient group almost peculiar to the islands 
of the South Pacifie Ocean. 
If this allocation be correct, P. omphala may be cousidered as especially 
representative in this country of the fauna characterizing New Zealand at 
the present day, and our most primitive form of the genus. 
Charopa, however, differs from Discus chietly in the tendency of the 
upper res to recede at its junction with the penultimate whorl and form 
an incipient sinus; but this feature, 
Fic. 247. 
ae though distinctly shown in Edwards’ 
Pyramidula oniphala on > d ayive 
(Edwards ms.), x4. Original figure (fig. 246) of the whorl- 
_ After photograph of Sculpture of P. omphala, is not con- 
the Irish Muceem. firmed by the illustration here given 
(fig. 247), which is from an enlarged 
photograph of the type specimen in the British Museum, and does not 
appreciably differ from the species of the sub-genus Déscas in the character 
of its form and sculpture. 
BRITISH ISLES. 
Oligocene—In the Isle of Wight. it is recorded by Dr. Sandberger from the 
Bembridge limestone at Sconce; by Mr. Charles Ashford from the Osborne series, 
and from B embridge, Hempstead, Whitecliff Bay, ete., in the Bembridge series. 
In South Hants., it has heen found by Mr. Searles Wood in the freshwater bed 
at Hordwell Cliff. 
