TRILOBIDAE 81 



twelve bristles. Six eversible lips present, each strengthened 

 internally by three dark, incurved, cuticular ribs. Oesophagus 

 cylindroid, narrowing a little behind. Spicules stout, browTi- 

 ish, curved laterally at the tips. Two accessory pieces 

 present, curved like the spicules distally. Testes paired, 

 opposed, outstretched. Female genital tube single, anterior, 

 outstretched. Caudal glands apparently preanal. Spinneret 

 present, armed with two bristles. 



Hab. Marine. 



Genotype : D. fissidens Cobb, 1920. 



Cobb, 1920, Contr. Sci. Nematol., ix, 281 and key. 



14. Dintheria de Man, 1921. 



Cuticle finely striated, without bristles or lateral alae. 

 Head with six bristles. Lateral organs large, transversely 

 elliptical, with posterior border probably interrupted. Buccal 

 capsule and oesophagus as in Monhystera. Caudal end of male 

 with a series of median preanal papillae. Accessory piece 

 absent. Spicules broad and short. Caudal glands and 

 spinneret probably absent. Female unknown. 



Hab. Soil. 



Genotype : D. tenuissima de Man, 1921. 



de Man, 1921, Capit. Zool, i, 9. 



15. Monohystrella Cobb, 1918. 



Buccal capsule more elongate than in Monhystera. Oesoph- 

 agus with a rather distinct pyriform bulb posteriorly. 

 Remaining characters, according to Cobb, are as in Monhystera. 

 Male unknown. 



Hab. Fresh water. 



Genotype : M. plectoides Cobb, 1918. 



Cobb, 1918, Cojitr. Sci. Nematol, vii, 203. 



Micoletzky (1922) has suggested that Monohystrella should 

 be regarded as a subgenus of Terschellingia. The condition 

 of the female genital tube and the presence of an oesophageal 

 bulb induce us to retain it as a genus nearer to Monhystera 

 than to Terschellingia. 



16. Cephalobellus Cobb, 1920. 



Cuticle rather coarsely striated. Head not distinct, sub- 

 truncate, without bristles. Lateral organs absent or obscure. 

 Six lips probably present. Pharynx conoid or pjrramidal, 

 small. Oesophagus cylindroid, with pjTiform posterior bulb. 

 Caudal end of male conical, without alae, but with a pair of 

 elongate subventral preanal papillae and two median postanal 

 papillae. A single slender spicule of irregular shape. Testis 



SYN. NEM. G 



