Syncheilaxonchium Coomans & Nair, 1971

Naz, Tabbasam & Ahmad, Wasim, 2012, Description of two new and five known species of the genus Axonchium Cobb, 1920 (Nematoda: Dorylamida) from India with diagnostic compendia and keys to species of the genera Axonchium and Syncheilaxonchium Coomans & Nair, 1975, Zootaxa 3264, pp. 1-37 : 36

Key to species of the genus Syncheilaxonchium Coomans & Nair, 1971

1 Anterior genital branch completely absent..................................................................2

- Anterior genital branch present........................................................................... 4

2 Constriction between two parts of pharynx very deep, abutting each other................................. asacculum

- Constriction between two parts of pharynx not very deep...................................................... 3

3 Lip region truncate; almost indistinct constriction between two parts of pharynx; two caudal pores on each side...................................................................................................... parassaculum

- Lip region rounded; isthmus-like structure present between two parts of pharynx; one caudal pore on each side... banaticum

4 Vagina directed posteriad............................................................................... 5

- Vagina straight........................................................................................ 7

5 Lip region rounded with distinct cephalic sclerotization............................................. singaporense

- Lip region without cephalic sclerotization..................................................................6

6 Cardia conoid; tail truncate with broadly rounded terminus, caudal pore one on each side....................... indicum

- Cardia cylindrical; tail slightly clavate, caudal pores two on each side.................................... deconincki

7 Amphids labial, fovea duplex...................................................................... sturhani

- Amphids post-labial, fovea simple........................................................................8

8 Amphidial fovea occupying almost entire lip region width at that level; males absent................................ 9

- Amphidial fovea smaller, not occupying the entire lip region width; males present................................. 10

9 Body length 1.0 mm; constriction between two parts of pharynx very deep; prerectum 5–6 anal body widths long; tail clavate............................................................................................. amalgans

- Body length 2.3 mm; both part of pharynx separated by isthmus-like portion; prerectum 2 anal body width long; tail broadly conoid........................................................................................ baldum

10 Lip region more or less truncate; female tail more or less clavate with very short conoid protoplasmic core; spicules slender; 34–38 µm long............................................................................... .. coomansi

- Lip region hemispheroid; female tail hemispherical; spicules broad, more than 40 µm long.......................... 11

11 Anterior pharynx slender with a valved spindle-shaped region; tail tip cuticle less than half the tail length............ nairi

- Anterior pharynx quite muscular without valved spindle-shaped region; tail tip cuticle more than half the tail length.................................................................................................... .. rotundum