56 ASCAROIDEA 



25. Plectus Bastian, 1865. 



Syn. Plectoides de Man, 1904 (as subgenus) ; Anthonema 

 Cobb, 1906; Pycnolaimus Cobb, 1920. 



Cuticle transversely striated, with scattered fine bristles. 

 Lateral alae present. Head may or may not be distinct, 

 with four or six bristles. Lateral organs elliptical or circular, 

 or semicircular and open behind. Lips, if distinguishable, 

 three or six. Buccal cavity elongate, three-sided. Male of geno- 

 type and most other species unknown. When known, the male 

 usually has an accessory piece, preanal and postanal papiUae 

 and a single testis. Female genital tubes paired, symmetrical, 

 and short, with a long reflexion. Caudal glands present. 



Hab. In moss, roots of plants, moist soil, etc. ; also in fresh 

 water. 



Genotype : P. parietinus Bastian, 1865. (See Stiles and 

 Hassall, 1905, U.S. Dept. Agric, Bur. Anim. Inclust, Bull. 79, 

 103). 



Bastian, 1865, Trans. Linn. Soc. London, xxv, 118; Mico- 

 letzky, 1914, Zool. Jahrb., Syst., xxxvi, 454; 1922, Arch. f. 

 Naturg., Abt. A, Ixxxvii, 211. 



25a, Subgenus Wilsonema Cobb, 1913. 

 Subgenus of Plectus, according to Micoletzky (1922). 

 Plectus with the anterior end furnished with lamellar 

 cuticular expansions or processes. 



Hab. Soil. 



Genotype : W. {Plectus] cephalatum (Cobb, 1893). 



Cobb, 1893, Nematode Worms found attacking Sugar-cane, 

 N. South Wales Agric. Dept; 1913, Journ. Washington Acad. 

 Sci., iii, 443 ; Micoletzky, 1922, Arch.f. Naturg., Abt. A, Ixxxvii, 

 241. 



26. Aplectus Cobb, 1914. 



Cuticle finely striated. Lateral alae present. Bristles 

 present in the neck region. Lateral organs circular. Lips very 

 indistinct. Buccal capsule long, probably in two parts, the 

 anterior part narrow and tubular, the posterior a muscular 

 pharynx. Oesophagus cylindrical, with a small bulb poste- 

 riorly. Caudal end of male with three protrusible supplemen- 

 tary organs and postanal bristles. Spicules rather strong. 

 Two rather strong, slightly bent accessory pieces present. 

 Testes paired, opposed, outstretched. Female genital tubes 

 paired, symmetrical, reflexed. Caudal glands and spinneret 

 present. 



Hab. Marine. 



Genotype : A. antarcticus Cobb, 1914. 



Cobb, 1914, Conlr. Sci. Nematol., i, 12. 



