Eukiefferiella Thienemann (Figs 43–46)

Head capsule narrow, yellow to dark brown. Occipital margin darkened, broad. Antenna with 4–5 segments, premandible broad with one apical tooth. Mandible with 3–4 inner teeth, apical tooth shorter than combined width of inner teeth; mola with 1–5 spines. Mentum striped, with 1 or 2 median and 4–5 lateral teeth. Ventromental plates are narrow, creating an appearance of a dark triangle below the last lateral tooth of mentum.

Remarks: Eukiefferiella is very similar to Tvetenia and the most reliable character separating their subfossils is the position of setae submenti that are close to the base of the mentum in Eukiefferiella but well below the mentum in Tvetenia . Moreover, head capsule of Tvetenia is usually pale, while head capsule of Eukiefferiella is light brown to dark brown (Schmid 1993).

Eukiefferiella claripennis (Lundbeck, 1898), E. coerulescens (Kieffer, 1926), E. minor (Edwards, 1929) / fittkaui Lehmann, 1972 and E. brevicalcar (Kieffer, 1911) / tirolensis Goetghebuer, 1938 have been so far recorded in the Tatra Mts. lakes (Bitušík 2004; Novikmec et al. 2015).

Subfossil remains occurred relatively frequently in lakes situated at lower altitudes, especially in lakes with strong inlet stream.

Four morphotypes were distinguished.

Key to morphotypes:

1 Mentum with single median tooth........................................................................ 2

- Mentum with bifid median tooth................................................ Eukiefferiella claripennis - type B

2 Mentum with 4 lateral teeth....................................................... Eukiefferiella devonica - type

- Mentum with 5 lateral teeth............................................................................. 3

3 Median mental tooth relativelly narrow, about 2x as broad as first lateral tooth............. Eukiefferiella brevicalcar - type

- Median mental tooth broad, more than 3x as broad as first lateral tooth....................... Eukiefferiella fittkaui - type