CYLINDROLAIMINAE 51 



8. Aulolaimus de Man, 1880. 



Cuticle unstriated. No lateral alae or bristles. Head not 

 distinct, without lips or bristles. Lateral organs apparently 

 absent. Buccal capsule an elongate, thin-walled, narrow tube, 

 much longer than the oesophagus. Tail of male with a few 

 median preanal papillae. Spicules slender. A single acces- 

 sory piece, bent posteriorly. Female genital tubes paired, 

 symmetrical. Caudal gland apparently absent. 



Hab. Sandy soil or fresh water. 

 Genotjrpe : A. oxycephalus de Man, 1880. 



de Man, 1880, Tijdschr. Nederl. dierk. Vereen., Leiden, 30; 

 1884, Die frei . . . lebenden Nematoden der Niederl. Fauna, 

 78. 



9. Isolaimium Cobb, 1920. 



Cuticle apparently unstriated. Lips and cephalic bristles 

 absent. Buccal capsule tubular. Oesophagus " plain," with- 

 out median or posterior enlargement. Tail of male bluntly 

 conical, with four pairs of papillae. Six papiUiform supple- 

 mentary organs present. Spicules slender, blunt. A single 

 slender accessory piece present, with a very small posterior 

 process. Testes paired, opposed, outstretched. Female 

 genital tubes opposed, reflexed. 



Hab. Soil. 



Genotype : I. papillatum Cobb, 1920. 



Cobb, 1920, Contr. Sci. Nematol., ix, 258 and key. 



10. Cryptonehus Cobb, 1913. 



Cuticle finely striated, without bristles. Lateral alae 

 present. Head not distinct, with six indistinct lips and a 

 crown of very small papillae. Buccal capsule tubular, like 

 that of Cylindrolaimus, but with a small dorsal tooth at its 

 base. Oesophagus without bulb. Male unknown. Vulva in 

 middle region of body. Female genital tube single, out- 

 stretched. Caudal glands and spimieret present. 



Hab. About roots of fresh-water plants. 

 Genotype : C. nudus Cobb, 1913. 



Cobb, 1913, Journ. Washington Acad. Sci., 441 ; Micoletzky, 

 1922, Arch. f. Naturg., Abt. A, Ixxxvii, 210. 



11. Ceramonema Cobb, 1920. 



Cuticle with coarse annulations, each composed of eight 

 imbricated elements. Neck region with small bristles in 

 longitudinal rows. Six cephalic bristles present. Lips indis- 

 tinct. Lateral organs crook-shaped. Buccal capsule very 

 slender. Oesophagus " plain," slightly expanded behind. 



