A partial revision of the marine nematode genus elzalia (monhysterida: xyalidae) with new characters and descriptions of two new species from khung kraben bay, East Thailand.

Elzalia bipectinellan. sp. and E. tuberculatan. sp. from Thailand are described and the males of three species from the Gulf of Mexico, E. federiciCastillo-Fernandez and Lambshead (1990), E. kimaeCastillo-Fernandez and Lambshead (1990), and E. poliCastillo-Fernandez and Lambshead (1990) are re-described from type and topotype specimens using light and scanning electron microscopy. New morphological characters are described that include ornamentations at the distal end of the spicula and features of the gubernaculum including the manus with digits, pontis with sensory receptor and accessory process, and the condylus with either conical or foliate projections. Also, ejaculatory and rectal glands are described for the first time for Elzalia. The relevance of the new characters to the taxonomy of Elzalia is discussed. A key to identification of males is provided. A generalized description of females is given, although characters are lacking by which females of each species may be identified.