DRILONEMIDAE 241 



2. Pierantonia nom. nov. 



Syn. Cephalonema Pierantoiii, 1916, nee Cobb, 1893. 



Head distinct, composed of two lateral thickenings, between 

 which is the mouth. Mouth imarmed, without papillae. 

 Oesophagus non-muscular, not distinct from intestine. Sexes 

 constantly found in copula. Male much smaller than female. 

 Spicules absent. Tail of female suddenly constricted, with 

 terminal spike. Vulva at about the posterior fourth of the 

 body, or behind it. 



Hab. Coelomic cavity of Earthworms. 

 Genotype : (by page precedence) C. microcephalum Peiran- 

 toni, 1916. 



Pierantoni, 1916, Boll. Soc. Nat. Napoli, xxviii, 149. 



3. Pharyngonema Pierantoni, 1923. 



Neck region swollen. Anterior end with minute bristles. 

 An ovoid, muscular pharyngeal bulb present, followed 

 immediately by the intestine. Male unknown. Tail of 

 female short, acutely pointed. Vulva at about the middle 

 of the body. 



Hab. Coelomic cavity of Earthworms. 

 Genotype : P. mekongiaiius Pierantoni, 1923. 



Pierantoni, 1923, Boll. Mus. Zool. Torino, xxxviii, (1) 2. 



4, Dicelis Dujardin, 1845. 



Mouth round, unarmed. Oesophagus short, muscular, 

 club-shaped, followed by a wider intestine. Tail, in both 

 sexes, blunt, carrying a pair of large, lateral sucker-like organs 

 surrounded by radiating fibres. Male with a pair of slightly- 

 curved spicules and an accessory piece. 



Hab. Sperm-sacs of Earthworms. 

 Genotype: Z)._yitena Dujardin, 1845. 



Dujardin, 1845, Hist. nat. cles Helminthes, Paris, 107 ; 

 Johnson, 1913, Quart. Journ. Micr. Sci., Iviii, 606, 608; 

 Pierantoni, 1916, Boll. Soc. Nat. Napoli, xxviii, 157. 



According to Johnson (1913), Dicelis is simply a new 

 name for larvae of Rhabditis inhabiting the nephridia and 

 spermiducal canals of earthworms. This, however, cannot 

 very well be the case, since Dujardin was evidently dealing 

 with adult worms and not larvae. 



SYN. NEM. • R 



