IRONINAE 143 



teeth at its anterior end. Dorsal tooth absent. Oesophagus 

 gradually swollen behind, without bulb. Caudal end of 

 male with nine median preanal supplementary organs. 

 Accessory piece with a posterior process. Testis single. Female 

 unknown. 



Hab. Marine (in sand). 



Genotype : D. sabulosus Southern, 1914. 



Southern, 1914, Proc. R. Irish Acad., xxxi, 31. 



10. Gonionchus Cobb, 1920. 



Cuticle very coarsely striated, with submedian bristles 

 throughout. Head not distinct, with six lips having " hinged " 

 terminal prolongations. Ten cephalic bristles present. 

 Lateral organs large, spiral. Pharynx wide, funnel-shaped, 

 containing two submedian blade-like teeth anteriorly. 

 Oesophagus somewhat swollen behind, without bulb. Caudal 

 end of male without supplementary organs, caudal papillae or 

 special bristles, but with bristles similar to those on the body. 

 Spicules slender, their shafts straight near the root, curved 

 distally. Two inconspicuous accessory pieces present. 

 Testes paired, opposed, outstretched. In connection with 

 the male genital organs there are three pairs of preanal accessory 

 glands, with ducts leading to the cloaca. Female genital tubes 

 paired, opposed, outstretched, the posterior without ovary. 



Hab. Marine (in mud). 



Genotype : G. villosus Cobb, 1920. 



Cobb, 1920, Contr. Sci. Nematol., ix, 315 and key. 



11. Dolicholaimus de Man, 1888. 



Cuticle unstriated and without bristles or lateral alae. 

 Head with feebly-developed lips and without, or with very 

 short, bristles. Lateral organs in the form of grooves. 

 Pharynx elongate, divided by a constriction into a short 

 anterior and a much longer, probably six-sided, posterior 

 portion. At the base of the anterior portion there are three, 

 probably movable, teeth which project into the mouth-opening. 

 Oesophagus without posterior bulb. Caudal end of male with 

 preanal and postanal papillae. An accessory piece present. 

 Female genital tubes paired, reflexed. Caudal glands present. 



Hab. Marine. 



Genotype : D. marioni de Man, 1888. 



de Man, 1888, Mem. Soc. Zool. France, i, 31. 



12. Syringolaimus de Man, 1888. 



Cuticle unstriated and without bristles. Head with 

 feebly-developed lips and without bristles. Lateral organs 



II 



