Description of Aphasmatylenchus liberiensis n. sp., and observations on the other species of the genus

Summary- The population From Liberia reporred as Aphasmatylenchus nigeriemis by Vovlas et al. (1991) is considered ro be a new species and is described and illustrared here as A. liberiensis n. sp. Irs primary distinguishing characteristics are the unsec-tored first lip annulus, the absence of sperm in the female genital tract, and the absence of males. Light and scanning electron microscopy observations were conducred on West African Aphasmatylenchus populations and the head parrerns for ail members of the genus are illusrrated. Variabiliry of exrernal morphological characteristics was very low and the genus appears homoge-neous in general morphology with the exception of the configuration of the first lip annulus. Fasciculi were observed for the first time in A. nigeriensis from south-western Ivory Coast, and filiform appendices similar to the appendices previously identi-fied in the genus Radopholus were detected on the edge of the anterior cloacallip of A. straturatus and A. variabilis; the presence of nerves in these structures cannot be ascerrained with SEM. © Elsevier- ORSTOM Résumé- Description d'Aphasmatylenchus liberiensis n. sp. et observations sur les autres espèces du genre Aphasmatylenchus Sher, 1965 (Nentatoda: Hoplolaimidae)- La population d'Aphasmacylenchus précédemment identifiée comme A. nigeriensis par Vovlas et al. (1991) est considérée comme une nouvelle espéce, décrite et illustrée ici comme A. libe-riensis n. sp.; ses principaux caractères distinctifs sont le premier anneau céphalique non divisé, l'absence de spermarozoïdes dans le tractus génital de la femelle et l'absence de mâles. Des observations en microscopie électronique à balayage et optique ont été conduires sur des populations ouest-africaines d'Aphasmacylenchus; la morphologie externe de la capsule céphalique es