Identification Key: 3

Key Position: 3	Back to (2b)
3a. Test ventrally depressed, almost circular dorso-ventrally, anterior angle varies between 15-40 degrees, posterior slope ill-defined or practically absent. Height/length ratio is low (0.4 - 0.5). Proceed to 4	3b. Test less depressed on ventral side than in 3a, elliptical in dorsal view. Anterior angle varies between 45-60 degrees and posterior angle well defined. Height/length ratio high (0.5 - 1.1). Proceed to 5