Key to valid ornata species (see Table 3) 1. Anterior part of body is very sharp-pointed. S. stenocephalus - Anterior part of body is not sharp-pointed. 2 2. Cephalic setae length more than or equal to head diameter. 3 - Cephalic setae length less than head diameter. 4 3. Length of spicules along arc is equal to cloacal body diameter. S. macramphis - Length of spicules along arc is more than cloacal body diameter. S. longisetosa 4. Diameter of amphideal fovea is less than or equal to 75% corresponding body diameter. S. parvamphis sp. n. - Diameter of amphideal fovea is more than 75% corresponding body diameter. 5 5. c’ = 4.5. S. abyssalis - c’> 4.5. S. ornata ; Published as part of Yang, Peipei, Guo, Yuqing, Chen, Yuzhen & Lin, Rongcheng, 2019, Four new free-living marine nematode species (Sabatieria) from the Chukchi Sea, pp. 31-54 in Zootaxa 4646 (1) on page 45, DOI:10.11646/zootaxa.4646.1.2, http://zenodo.org/record/3346313