Table 4 Measurements [in μm] of eggs of Richtersius coronifer s.s. (Richters, 1903) from the Billefjorden population (eggs mounted in Hoyer’s medium; process base/height ratio is expressed as percentage; N – number of eggs/structures measured, RANGE refers to the smallest and the largest structure among all measured specimens; SD – standard deviation)
Character | N | Range | Mean | SD | ||
|---|---|---|---|---|---|---|
Egg bare diameter | 30 | 173.2 | – | 233.4 | 200.6 | 16.1 |
Egg full diameter | 30 | 201.5 | – | 263.7 | 233.0 | 16.6 |
Process height | 90 | 13.0 | – | 28.3 | 21.7 | 3.2 |
Process base width | 90 | 2.7 | – | 6.9 | 4.6 | 0.9 |
Process base/height ratio | 90 | 12% | – | 33% | 22% | 5% |
Inter-process distance | 90 | 4.4 | – | 13.2 | 8.4 | 1.8 |
Number of processes on the egg circumference | 30 | 60 | – | 77 | 67.1 | 4.5 |