Euphemites pustula n.sp.

PI. 1 figs 1-3

Description. Shell very small, relatively thin shelled, symmetrically coiled planispiral, anomphalous. Protoconch concealed, seemingly minute, planispiraI. Teleoconch planispiral with involute whorls; last whorl completely embracing earlier whorls; about 18 strong sharp spiral cords in the first half volution; perinductura pustules continuing from the spiral cords occur in the last half volution; selenizone obscured by perinductura; shell consisting of 2 layers. Height of aperture corresponds to that of shell; slit seemingly broad and small.

Types. Holotype (F78341), 2 figured paratypes (F78342) and 4 additional paratypes (F78529).

Type locality. About 250 m west of Babbinboon Lane, Swains Gully, 15 km south-west of Somerton, NSW (Locality 25).

Stratigraphic position. In bioc1astic limestone, 130 m above the base of Namoi Formation.

Geographic distribution. Swains Gully.

Geological age. Middle Tournaisian.

Etymology. Referring to perinductura pustules.

Remarks. Euphemites minutus Maxwell and Euphemites labrosa Campbell & Engel both have a globular form with a narrow and deep umbilicus. Euphemites pustula n.sp. resembles E. minutus in having a number of spiral cords, but differs in baving a narrow peripheral profile, perinductura pustules and in lacking an umbilicus. The mode of life and shell structure of Euphemites has been discussed by Moore (1941), Yochelson (1960), Linsley (l978b), and Harper & Rollins (1985). Euphemites pustula is characterised by perinductura pustules which appear to be the continuation of the spiral cords of the shell. The shells also lack the second layer of coinductura in and adjacent to the aperture. Euphemites pustula would have had mantle flaps covering almost the entire shell lacking the secondary deposit of coinductura.