Lagynochthonius, Beier, 1951

Li, Yun-Chun, Liu, Huai & Shi, Ai-Min, 2019, A new cave-dwelling species of Lagynochthonius (Arachnida: Pseudoscorpiones: Chthoniidae) from Yunnan Province, China, Zootaxa 4571 (1) : -

Key to the species of Lagynochthonius known from China

1. Carapace with eyes.................................................................................... 2

- Carapace without eyes or eyespots................................................... L. bailongtanensis sp. nov.

2. Posterior pair of eyes reduced to eyespots.................................................................. 3

- Posterior pair of eyes with flattened lenses.................................................................. 5

3. Trichobothrium sb 2.0 times as far from st as far from b; palpal femur 5.8 times as long as broad............................................................................................ L. brachydigitatus Zhang & Zhang, 2014

- Trichobothrium sb 1.3–1.5 times as far from st as far from b; palpal femur 3.0–4.0 times as long as broad................ 4

4. Tergites III–V each with 6 setae; palpal femur 3.0 times as long as broad (length 0.45 mm), hand 2.0 times longer than broad.................................................................................. L. sinensis ( Beier, 1967)

- Tergites III–V each with 4 setae; palpal femur 4.0 times as long as broad (length 0.60 mm), hand 2.7 times longer than broad................................................................................ L. tonkinensis ( Beier, 1951)

5. Chelal fingers without intercalary teeth.................................................................... 6

- At least one finger of chela with intercalary teeth............................................................ 7

6. Palpal femur 6.3–6.4 times as long as broad (length 0.70–0.75 mm), chela length 0.95–1.00 mm.................................................................................................. L. leptopalpus Hu & Zhang, 2012

- Palpal femur 4.8–5.5 times as long as broad (length 0.55–0.58 mm), chela length 0.75–0.93 mm .. L. niger Hu & Zhang, 2012

7. Tergites I–II each with 2 setae; both chelal fingers with intercalary teeth; chela 6.9–7.2 times as long as broad (length 0.65– 0.69 mm)................................................................... L. medog Zhang & Zhang, 2014

- Tergites I–II each with 4 setae; only fixed chelal finger with intercalary teeth; chela 5.8–6.4 times as long as broad (length 0.58–0.76 mm)................................................................ L. harveyi Hu & Zhang, 2014