Key to the Nebela collaris-tincta group

1Shell wider than long2
Shell longer than wide3
2L. 72–111 µm, B. 90–133 µm, strongly flattened, with short neckN. flabellulum
Smaller species, L. 60  µm, B. 70  µm, compressed, without neckN. acolla
3Shell > 100 µm4
Shell < 100 µm6
4Shell compressed5
Shell not compressedN. golemanskyi
5Shell with lateral ridge, wide ovoid, with wide linear aperture 24–27 µmN. aliciae
Shell without lateral ridge, pyriform, with very short (2.7 ± 0.9  µm high or almost absent) neck, with aperture slightly or strongly curved, or sometimes linear, 28–32 µmN. bohemica

N. collaris

6With protruding neck and narrow aperture 19–23 µm, up twisted7
With short neck (4.6 ± 0.2 high), with linear wide aperture 24–26 µm9
7Aperture  curved 8
Aperture not curvedN. pechorensis
8L. 80–89  µm, B. 53–65 µmN. guttata
L. 67–78  µm, B. 50–62 µmN. gimlii
9Shell ovoid or elongated elliptic, L/B = 1.3–1.4N. tincta
Shell rounded, L/B = 1.2–1.3N. rotunda

Modified after Kosakyan et al., 2012

Ferry Siemensma, created February 13, 2022; last modified February 16, 2022
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