Ilanga

Vilvens, Claude & Williams, Suzanne T., 2020, New species of Ilanga (Gastropoda: Trochoidea: Solariellidae) from the Indo-West Pacific, Zootaxa 4732 (2), pp. 201-257 : 215-216

Key 2: Key to Ilanga species of Indo-Pacific area studied in this work

1. subsutural axial pleats visible on second or third whorl........................................................ 2 - no obvious subsutural axial pleats on whorls.............................................................. 13 2 (1). umbilical rim rounded to weakly subangulate............................................................... 3 - umbilical rim angulate................................................................................. 6 3 (2). no axial threads inside umbilicus........................................................................ 4 - axial threads inside umbilicus........................................................................... 5

4 (3). conical shape with nearly flat whorls................................................... I. cosmia

- conical to slightly cyrtoconoidal shape, convex whorls.................................. I. corrineae

5 (3) rather depressed spire, 4 Pi, very large umbilicus........................................... I. comes - rather elevated spire, 5 Pi, moderately large umbilicus.................................. I. dongshaensis

6 (2). always axial threads inside the umbilicus.................................................................. 7

- no axial threads always present inside the umbilicus.......................................................... 9

7 (6). ± 3 spiral cords around umbilicus, central base area reticulate............................... I. oxeia

- usually one single spiral cord around the umbilicus.......................................................... 8

8 (7). rounded periphery without spiral cords.............................................. I. eurystoma

- subangulate periphery, faint spiral cords on periphery.................................... I. harrytaylori

9 (6). depressed, lenticular................................................................................. 10

- at most moderately depressed........................................................................... 11

10 (9). strongly depressed, spiral cords around the umbilicus, up to 19 mm............................. I. gotoi

- a single spiral cord around the umbilicus.......................................... I. euryomphalos

11 (9). rather elevated spire............................................................ I. navakaensis

- moderately depressed spire only........................................................................ 12

12 (11).5 Pi....................................................................... I. stephanophora

- 4 Pi......................................................................... I.polygramma

13 (1). umbilical rim only weakly subangulate.................................................. I. fulgens

- umbilical rim angulate or at least subangulate.............................................................. 14