Agnesia reticulata n.sp.

PI. 8 figs 1-3

Description. Shell medium, trochiform, sinistral, moderately phaneromphalous. Protoconch coiling inward and hidden by later whorls, apex a funnel-like hole. Teleoconch conical with sunken top, whorl profile gently arched between sutures, rather deep, base gently convex, ornamentation of opisthocline collabra1 lirae and weaker spiral threads making small nodes in intersections. Selenizone relatively narrow; lower margin of selenizone on sutures with a narrower and deeper channel in the middle of the elevated selenizone; regularly spaced lunulae in the deeper channel and regularly spaced inclined streaks in outer selenizone. Aperture subcircular with inner lip thin, arcuate, deflected towards umbilicus; outer lip opisthocline from the upper suture, slit seemingly very narrow; parietal inductura lacking.

Types. Holotype (F78406) and 3 paratypes (F78410, F78416).

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

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

Geographic distribution. Type locality only.

Geological age. Middle Tournaisian.

Etymology. Referring to the network of obliquely intersecting linear ridges.

Remarks. The shell consists of two distinct layers. Of interest is the mark of the deeper channel and the 1unulae remaining on the inner shell layer.