GENERA INCERTAE SEDIS 249 



Cuticle firm and thick, containing two systems of fibres crossing 

 each other. Musculature holomyarian, not interrupted by 

 longitudinal fields. Oesophagus relatively short. Tail very 

 short. Reproductive organs unknown. 



Hab. Marine (1,950 fathoms). 



Genotype : P. proJundissi7na v. Linstow, 1888. 



V. Linstow, 1888, Challenger Exp., Zool., Ixxi, 11. 



The description is based on two immature specimens. 



26. Pseiidochromadora Daday, 1901. 



Body of uniform thickness, except posteriorly, where it 

 tapers gradually. Cuticle thick, with well-marked striations. 

 No cephalic papillae or bristles, but near the anterior end there 

 are four conspicuous sucker-like " warts." Buccal cavity 

 without cuticular structures. Oesophagus with a more or 

 less oval posterior bulb, having an oval lumen thickly lined 

 with cuticle. Male unknown. Tail of female relatively short, 

 with a short, " leaf-shaped " terminal point. Vulva in 

 middle of body. Female genital tubes paired. A single ( ?) 

 caudal gland present. 



Hab. Fresh water. 



Genotype : P. quadripapillata Daday, 1901. 



Daday, 1901, Termes. Filzetek, Budapest, xxiv. 7; Mico- 

 letzky, 1922, Arch.f. Naturg., Abt. A, Ixxxvii, 620. 



27. Pterygifer v. Linstow, 1907. 



Cuticle transversely striated. Head rounded, with four 

 movable, wing-like plates, which are attached in front, con- 

 cave behind. Each plate has at its posterior end an inwardly- 

 projecting hook-like process. Oesophagus one-fifth of the 

 total length. Male unknown. Tail of female rounded. 

 Vulva somewhat behind the middle of the body. Oviparous. 



Hab. Parasitic in a Fish {Symbranchus). 

 Genotype : P. tetrwpteryx v. Linstow, 1907. 



V. Linstow, 1907, Mitt. Zool. Mus. Berlin, iii, 255. 



V. Linstow's description and figure of this worm are 

 practically unintelligible, and though the structure of the 

 head, as described, is somewhat reminiscent of Habronema 

 and Hedruris among the Spiruridae, we are quite unable to 

 assign the worm to a definite position. 



28. Scolecophilus Baylis & Daubney, 1922. 



Body short and stout, tapering more gradually in front 

 than behind. Cuticle thin and smooth. Lateral fields very 

 conspicuous, broad, granular, increasing in width posteriorly 



