Comparative morphology of the anterior end of selected taxa of Merliniidae Siddiqi, 1971 (Nematoda: Tylenchoidea), with morphological characterisation of two species and taxonomic keys to several genera Author Ghaderi, Reza Author Karegar, Akbar Author Miraeiz, Esmaeil Author Hashemi, Kobra text Zootaxa 2017 4300 4 571 588 journal article 32552 10.11646/zootaxa.4300.4.6 b3b53404-5f24-4055-8ecf-28f7b38968f6 1175-5326 839278 1AF156E1-FBBD-4930-B65F-D420E57477EF Key to genera of Merliniidae [List of genera according to Sturhan (2012) and Siddiqi & Sturhan (2014) ] 1. Deirids absent........................................................................................2 - Deirids present........................................................................................3 2. Lateral field with four incisures; caudal cuticle of females and juveniles without refractive inner layer; cuticle without longitu- dinal striae................................................................................. Telomerlinius - Lateral field with six incisures; caudal cuticle of females and juveniles with refractive inner layer; cuticle mostly with longitu- dinal striae................................................................................. Geocenamus 3. Cephalic framework slightly sclerotized ( Fig. 2 G–N)......................................................... 4 - Cephalic framework heavily sclerotized ( Fig. 2 A–F).........................................................5 4. Cephalic radial grooves present; female tail pointed to subcylindrical, with refractive inner cuticle layer at terminus, but with- out distinct hyaline portion; four lateral incisures in J4................................................. Merlinius - Cephalic radial grooves absent; female tail elongate-conoid to pointed, without refractive inner cuticle layer at terminus, but with distinct hyaline portion; six lateral incisures in J4.................................................. Nagelus 5. Female tail with refractive inner cuticle layer..................................................... Paramerlinius - Female tail without refractive inner cuticle layer.............................................................6 6. Female stylet very long, more than 90 µm...................................................... Macrotylenchus - Female stylet shorter, less than 50 µm.....................................................................7 7. Pharyngeal glands mostly overlapping intestine; head usually with 2–5 transverse annuli; female tail pointed to cylindrical; four lateral incisures in J4................................................................... Pratylenchoides - Pharyngeal glands offset from intestine; head with 5–10 transverse annuli; female tail cylindrical; six lateral incisures in J4........................................................................................... Amplimerlinius