ALAIMIDAE 105 



44. Disconema Filipjev, 1918. 



Cuticle finely striated. Head without lips, but with six 

 labial papillae, and ten bristles in a single crowai. Lateral 

 organs extremely large, oval, with some signs of concealed 

 spirals. Buccal cavity absent. Oesophagus with indistinct 

 bulb. Female genital tubes paired, outstretched. 



Hab. Marine. 



Genotype : D. alaima Filipjev, 1918. 



Filipjev, 1918, Trav. Lab. ZooL, Stat. Biol. Sebaslopol, 

 Ser. II, No. 4, 305. 



45. Prosphaerolaimus Filipjev, 1918. 



Cuticle finely striated. Head not distinct, with six lips 

 and two crowns each of six papillae. Four cephalic bristles 

 present, and behind these many supplementary bristles. 

 Lateral organs large, circular. " Oral cavity nearly absent " ; 

 [the figure does not enable us to form a conception of its 

 structure]. Oesophagus cylindrical, without bulb or posterior 

 swelling. Tail of female long and tapering. Female genital 

 tube (single?) outstretched. Male apparently unknown. 



Hab. Marine. 



Genotype : P. eurypharynx Filipjev, 1918. 



Filipjev, 1918, Trav. Lab. ZooL, Stat. Biol. Sebastopol, Ser. II, 

 No. 4, 303. 



Appenbix to Alaimidae. 

 a. Linhomoella Cobb, 1920. 



Cuticle finely striated, without bristles except towards 

 the anterior end. Head not distinct, without apparent lips, 

 but with a double crown of ten bristles. Lateral organs 

 spiral. The presence of a pharynx is uncertain. Oesoph- 

 agus cylindrical, without bulb. Caudal end of male with 

 a few bristles on each subventral line. Accessory piece 

 present, with a smaU process. " As to supplementary organs, 

 there are almost invisible ventral imiervations." Testes and 

 female genital tubes paired, opposed, outstretched. Caudal 

 glands and spinneret present. 



Hab. Marine. 



Genotype : L. exilis Cobb, 1920. 



Cobb, 1920, Contr. Sci. Nematol., ix, 254 and key. 



b. Mastodex Steiner, 1921 ( ?). 



Steiner (1921, Zool. Jahrb., Anat., xliii, 25) figures a worm 

 under the name of Mastodex kerguelensis Steiner. The indi- 

 vidual figured appears to be an immature one, with a simple, 

 club-shaped oesophagus. No buccal cavity is indicated. 



