Spirillina sp. 1 (Fig. 17:1, 2)

Remarks. This indeterminate species is assigned to Spirillina due to its planispirally enrolled, completely evolute test, rounded periphery and depressed sutures. This taxon also has shallow radiating corrugations, a long, thin and simple terminal aperture and a slight indent in the final coil of the test on the opposite side to the aperture (Fig. 17:1, 2). These features are very similar to Spirillina vivipara Ehrenberg 1843, Spirillina sp. 1 described by Parker (2009) and Spirillina sp. A (Hottinger et al. 1993). However, only a single fragmentary specimen was collected preventing detailed comparisons and a confident species identification from being made.

Distribution within study area. Sprillina sp. 1 was only found at site 51 in One Tree Lagoon 2.