ALAIMIDAE 101 



Ditlevsen, 1922, Vid. Medd. Naturh. Foren., Copenhagen, 

 Ixxiii, 2. 



30. Porocoma Cobb, 1920. 



Cuticle thin, finely striated, without bristles. Head with 

 ten bristles, also a ventral bristle-like organ just behind the 

 excretory pore. Mouth with relatively thick, minute lips. 

 Lateral organs probably absent. Buccal capsule absent or 

 vestigial. Oesophagus without bulb. Male unknown. Female 

 genital tubes parallel, posterior. Caudal glands present. 



Hab. Marine. 



Genotype : P. striata Cobb, 1920. 



Cobb, 1920, Contr. Sci. NematoL, ix, 236 and key. 



31. Nemella Cobb, 1920. 



Cuticle finely striated, without bristles. Head with four 

 bristles. Lateral organs small, with obvious internal ele- 

 ments. Oesophagus cylindrical. Two ocelli present, with 

 lenses. Caudal end of male without supplementary organs 

 or bristles. An accessory piece present, with a posterior 

 process. Female unknown. 



Hab. Marine. 



Genotjrpe : N. ocellata Cobb, 1920. 



Cobb, 1920, Contr. Sci. NematoL, ix, 236 and key. 



32. Schistodera Cobb, 1920. 



Cuticle thin, without bristles. Head without bristles. 

 Lateral organs large and deep, with strongly chitinized pos- 

 terior wall. Oesophagus expanding suddenly posteriorly. 

 Caudal end of male with a pair of inconspicuous preanal 

 bristles and two or three minute submedian postanal bristles. 

 A straight accessory piece present. Testes probably paired. 

 Caudal glands and spinneret present. Female unknown. 



Hab. Marine (among Algae and sand). 

 Genotype : S. exilis Cobb, 1920. 



Cobb, 1920, Contr. Sci. NematoL, ix, 231 and key. 



33. Stilbonema Cobb, 1920. 



Cuticle with plain striations, retrorse posteriorly, the re- 

 verse anteriorly. Body with very short, slender, submedian 

 bristles, six to nine striations apart. Head probably with a 

 ring of very small papillae and twenty bristles. Lateral 

 organs small, tubular, labial. Oesophagus very narrow, with 

 pyriform posterior bulb. Caudal end of male with a row 

 of acorn-shaped supplementary organs extending far forward. 

 Spicules slender [very broad in figure]. Two parallel 



