130 ASCAROIDEA 



Leiden, 127; Micoletzky, 1922, Arch. f. Naturg., Abt. A, 

 Ixxxvii, 419. 



3. Nudora Cobb, 1920. 



Cuticle with coarse transverse striations and with ten 

 longitudinal alae, each containing a series of V-shaped mark- 

 ings. Head not distinct, with much-thickened cuticle. Lips 

 apparently twelve. Six labial bristles and four longer cephalic 

 bristles present. In addition to these, six bristle-like labial 

 papillae. Lateral organs circular. Pharynx rather small, 

 with cup-shaped anterior portion and narrower posterior 

 portion, and containing a single large, forwardly-directed 

 tooth. Oesophagus with an anterior pharyngeal swelling, 

 separated from the rest by a constriction, and with a cylindroid 

 posterior bulb divided into two parts by a break in its muscu- 

 lature. Tail in both sexes with a few slender submedian 

 preanal and postanal bristles. Caudal end of male with two 

 " obscure " preanal supplementary organs. Spicules very 

 slender. Two stoutish accessory pieces present, somewhat 

 longer than the spicules. Female genital tube single, anterior, 

 outstretched. Caudal glands and spinneret present. 



Hab. Marine. 



Genotype : N. lineata Cobb, 1920. 



Cobb, 1920, Contr. Sci. Nematol, ix, 334 and key. 



4. Rhinema Cobb, 1920. 



Cuticle with coarse transverse striations and with twelve 

 longitudinal alae, each with a series of bifurcate spines pre- 

 senting a " fishbone-like " appearance. Head not distinct, 

 with six lips whose apices turn outwards. Six cephalic 

 bristles present. Lateral organs circular. Pharynx appar- 

 ently wide anteriorly and narrow jjosteriorly, containing a 

 forwardly-pointing dorsal tooth. Oesophagus with a special- 

 ized pharyngeal portion and expanding gradually behind into 

 a bulb-like swelling. Caudal end of male without supple- 

 mentary organs or papillae, but with a few small bristles at 

 the tip of the tail. Spicules slender. A single, slightly 

 sigmoid, partly protrusible, accessory piece present. Testes 

 paired, opposed, outstretched. Female genital tubes paired, 

 opposed, reflexed. Spinneret present. 



Hab. Marine. 



Genotype : E. retrorsum Cobb, 1920. 



Cobb, 1920, Contr. Sci. Nematol., ix, 335 and key. 



5. Oistolaimus Ditlevsen, 1922. 



Cuticle finely striated, with a few scattered bristles. Head 

 with a single crown of fine bristles. Lateral organs spiral^ 



