Two new species of free-living marine nematodes of the family Oxystominidae Chitwood, 1935 (Enoplida) with a review of the genus Thalassoalaimus de Man, 1893 from the Argentine coast Author Martelli, Antonela Author Russo, Virginia Lo Author Villares, Gabriela Author Pastor De Ward, Catalina T. text Zootaxa 2017 4250 4 347 357 journal article 33288 10.11646/zootaxa.4250.4.5 f96392dc-e97b-41db-9607-31cf6cd2d050 1175-5326 495299 F15232E9-A0DF-4A72-94EE-40ACB7277A3C Key to all known species of genus Thalassoalaimus (Based on male characteristics) 1. Tail without pointed tip....................................................................... T. brasiliensis - Tail with pointed tip...................................................................................2 2. More than 2 precloacal organs................................................................... T. pacificus - Two precloacal organs..................................................................................3 3. Cephalic setae more than 1/2 of the corresponding diameter....................................................4 - Cephalic setae less or equal than 1/2 of the corresponding diameter..............................................5 4. Gubernaculum more than 1/2 spicule length..................................................... T. nestori sp. n. - Gubernaculum less than 1/2 spicule length..................................................... T. macrosmaticus 5. Cephalic setae configuration: 6+6+4.......................................................................6 - Cephalic setae configuration: 6+4+4.......................................................................7 6. Cephalic setae less than 3 times the cephalic diameter from anterior end............................. T. mediterraneus - Cephalic setae more than 3 times the cephalic diameter from anterior end................................... T. tardus 7. c’ less than 2................................................................................... T. lissus - c’ greater than 2.......................................................................... T. septentrionalis