RHABDITIDAE 61 



with a posterior bulb. Male unknown. Female genital tube 

 single, anterior. Caudal glands absent. 



Hab. Sand, near coast. 



Genotype : W. typica de Man, 1921. 



de Man, 1921, Capit. Zool, i, 14. 



This diagnosis is based on a single immature female. 



g. Terschellingia de Man, 1888. 



Cuticle unstriated, with a few small bristles anteriorly. 

 Head distinct, without lips, but with small bristles. Buccal 

 capsule very small. Oesophagus extremely short, with a 

 large posterior bulb having a dilated lumen. Caudal end of 

 male without papillae. Spicules short. An accessory piece, 

 with two posterior processes, present. Female genital tubes 

 paired, opposed. Caudal glands and spinneret present. 



Hab. Marine. 



Genotype : T. communis de Man, 1888. 



de Man, 1888, 3Iem. Soc. Zool. France, i, 11 ; Micoletzky, 

 1922, Arch.f. Naturg., Abt. A, Ixxxvii, 183. 



gg. Subgenus Oligomonohystera Micoletzky, 1922. 



(Subgenus of Terschellingia.) * 



Lateral organs circular or slit-like. Buccal capsule small 

 and typical, or spacious. Female genital tubes paired, opposed. 



Hab. Marine and terricolous. 



Type : Terschellingia (O.) [Monhystera] elongata (Biitschli, 

 1874). 



Biitschli, 1874, Abhandl. Senckenb. naturf. Ges., Frankfurt 

 a. M., ix, 262 ; Micoletzky, 1922, Arch.f. Naturg., Ixxxvii, 168. 



h. Chronogaster Cobb, 1913. 



Cuticle finely striated, without bristles or alae. Head not 

 distinct, with four bristles. Lateral organs trapezoid, open 

 behind. Buccal capsule funnel-shaped. Oesophagus with a 

 posterior bulb. Caudal end of male with nine protrusible 

 preanal supplementary organs. Testes paired, opposed, out- 

 stretched. Female genital tube single, anterior, refiexed. 

 Caudal glands and spinneret present. 



Hab. Fresh water. 



Genotype : C. gracilis Cobb, 1913. 



Cobb, 1913, Journ. Washington Acad. Sci., iii, 443 and key. 



* Oligomonohystera was proposed by Micoletzky (1922) as a subgenus 

 of Monhystera. The only character serving to distinguish it from 

 Monhystera s.s. is the fact that the female genital tubes are paired. We 

 consider that this character excludes it from that genus, and suggests 

 its inclusion in the genus Terschellingia. 



