DESMODORINAE 137 



21. Pharetrolaimus de Man, 1921. 



Cuticle smooth. Head hemispherical, slightly distinct, 

 with two crowns each of six papillae, but without bristles. 

 Lateral organs small, pit-like. Buccal cavity tubular, narrow 

 and thin-walled, containing a spear-like tooth, which is 

 arrow-shaped in ventral view, with three posterior processes. 

 There are also apparently three very small denticles near the 

 anterior end. Structure of oesophagus uncertain. Male 

 unknown. Vulva in oesophageal region. Female genital 

 tube single, posterior, reflexed. Caudal glands absent. 

 (Description based on a single immature female). 



Hab. Soil. 



Genotype : P. sagittifer de Man, 1921. 



de Man, 1921, Capit. Zool, i, 42. 



K 22, Catalaimus Cobb, 1920. 



Cuticle very finely striated, without bristles. Head not 

 distinct, rounded, with six labial papillae and a crown of ten 

 short bristles. Lateral organs apparently horseshoe-shaped, 

 open behind. Pharynx with somewhat funnel-shaped anterior 

 portion, containing a long and slender, forwardly-directed 

 tooth, and an extremely long, slender, tubular posterior 

 portion, extending backwards behind the nerve-ring. Oesoph- 

 agus cylindroid, without bulb. A pair of ocelli present. 



■ Male unknown. " Ovaries probably double and reflexed." 

 Spinneret present. (Description based on a single immature 



I female). 



Hab. Marine. 



Genotype : C. acuminatus Cobb, 1920. 



Cobb, 1920, Contr. Sci. Nematol., ix, 308 and key. 



23. Laxus Cobb, 1894. 



Cuticle rather coarsely striated, with bristles throughout. 

 Head not distinct, with bristles. Lateral organs spiral. In 

 the genotype the oral cavity has transverse chitinoid ridges. 

 Pharynx narrow, " probably containing an obscure dorsal 

 tooth " [in L. sepientrionalis]. Oesophagus with anterior 

 swelling and spherical posterior bulb. Caudal end of male 

 with several pairs of submedian preanal and postanal bristles. 

 One or two accessory pieces present. Testis single, or paired, 

 opposed. Female genital tubes paired, opposed, reflexed 

 or outstretched. Caudal glands present. 



Hab. Marine (in sand). 

 Genotype : L. longus Cobb, 1894. 



Cobb, 1894, Proc. Linn. Soc. N.S.W., Sydney, (2) viii, 413; 

 1914, Contr. Sci. Nematol, i, 29. 



