In this article four species of Desmodoridae, Desmodora alberti sp. nov., Desmodora marci sp. nov., Desmodorella balteata sp. nov. and Desmodorella spineacaudata sp. nov. (Nematoda: Desmodoridae), are described from hydrothermal vents of the Pacific. The genus Desmodora is revised and lists of valid species are provided; four subgenera are reinstated as genera; Xenodesmodora is regarded as genus inquirendum. Definitions of some morphological structures are given.

Morphological features of the cuticular appendages, such as spines, thorns, setae and flaps are described on the basis of SEM pictures of three new and three known species of the Epsilonematidae from East African coasts. Epsilonema espeeli sp.n. is characterized by the presence of six subcephalic setae and a large number of hair-like spines on the dorsal body side; males are characterized by three pairs of copulatory thorns, three precloacal thorns and an anal tube; females have a large citucular flap covering the vulva. Metepsilonema iuvenisspinosum sp.n. is characterized by its small size, ornamentation and shape of the body annules, conspicuous inversions in direction of the body annules (3 dorsal inversions and 1 ventral inversion), oval amphid, 4 pairs of supporting setae of which the third pair is the longest one in the males and the last pair the longest one in the female, length of the spicules and the subdorsal spines on the female (and juveniles) tail. Perepsilonema ritae sp.n. is characterised by sexual dimorphism in: amphidial shape (slit-like in the males, spiral in the females), number of subcephalic setae (8 in the males, 6 in the females), ornamentation of the body annules, sudden broadening of the body just behind the ventral body curvature and a slender annule posterior to the ventral body curvature. Males have large copulatory thorns and slender spicules. Additional morphological information on Epsilonema parvospina Decraemer, 1982, Metepsilonema bermudae Lorenzen, 1973 and Perepsilonema kellyae Gourbault & Decraemer, 1988 is presented and important external characteristics are illustrated with SEM pictures. The external morphology of the ambulatory setae is compared between specimens of the Epsilonematidae and one species of Draconematidae (Dracograllus eira (Inglis, 1968)).

This article is a review of the subfamily Desmodorinae (Nematoda, Desmodoroidea) and two related genera within this subfamily, Croconema

Chromaspirina vanreuselae sp. n., Zalonema myrianae sp. n., Echinodesmodora moensi sp. n., and Metachromadora (Bradylaimus) nyalii sp. n. are described from coarse coral sands in the intertidal zone of beaches along the Kenyan coast. In Chromaspirina vanreuselae sp. n., 15 cheilorhabdia (instead of 12 which is typical for the Chromadorina) are found in the cheilostome. Zalonema Cobb, 1920, is restored to the genus level. Comments are given on the term ‘head region’, and on ontogenetic transformations of some morphological characters, such as amphidial shape, presence, number and position of subcephalic setae, and tail shape.

Two new epsilonematid nematode species from Kenyan intertidal areas are described: Bathyepsilonema anulosum sp.n. -characterized by the large number of body-annules (118-124); small unispiral amphid, straight ambulatory setae and the very small copulatory thorns of the males -and Leptepsilonema richardi sp.n., -characterized by the sexual dimorphism in the amphid, the ornamentation of the body cuticle and the umbrella shaped capitulum in the males.Abbreviations: a: body length divided by maximum body diameter; ABD: body diameter at level of anus; amph %: diameter of amphid as a percentage of the corresponding head diameter; Asl: length of the anteriormost seta ambulatoria of the external subventral row; ant: length of the anal tube; b: body length divided by pharyngeal length; c: body length divided by tail length; cs: length of cephalic setae; dcs: distance from the rostrum edge to cephalic setae; gub: length of gubernaculum; L: body length; lct: length of copulatory thorns; mbd: maximum body diameter of posterior body region; (mbd): minimum body diameter; mbd/(mbd): maximum body diameter divided by minimum body diameter; mbd ph: body diameter at level of pharyngeal bulb; N: number of body rings; ph: length of pharynx; spic: length of spicule measured along the arc; S Sph: length of subdorsal somatic setae in pharyngeal region; t: tail length; tmr: length of non-annulated tail region; V: position of the vulva as a percentage of the total body length from anterior.