ONCHOLAIMIDAE 149 



in the male, and a series of button-like, bristle-bearing promin- 

 ences. 



Hab. Marine. 



Genotype : H. laticollis Marion, 1870. 



Marion, 1870, Ann. Sci. Nat., Paris, ZooL, (5) xiii, Art. 14, 18. 



If this be a valid genus, it will require to be renamed on 

 account of the previous use of Heterocephalus. As, however, 

 its status is at present uncertain, we refrain from introducing 

 a fresh complication into the synonymy. 



b. Enoplostoma Marion, 1870. 



Body short and stout, especially anteriorly. Head with 

 numerous circumoral papillae and a crown of very stout, 

 recurved bristles. Buccal cavity rather small, armed with 

 three cuticular " pieces " of peculiar shape. Ocelli present. 

 Male with a single preanal supplementary organ. Spicules 

 short and thick, with serrated inner border. Two pairs of 

 accessory pieces present. 



Hab. Marine. 



Genot3rpe : (by page precedence) E. hirtum Marion, 1870. 



Marion, 1870, Ann. Sci. Nat., Paris, Zool., (5) xiii, Art. 14, 22. 



c. Lasiomitus Marion, 1870. 



Body elongate, with numerous bristles, sometimes arranged 

 in bunches, and longer and thicker near the head and cloacal 

 aperture. Head rounded in front. Buccal capsule narrow, 

 its wall strengthened by two long, slender chitinoid structures 

 which are expanded in front and behind. Two ocelli, with 

 lenses, present at the level of the base of the buccal capsule. 

 Oesophagus simple, slightly enlarged behind. Tail conical. 

 Male sometimes with a series of setiform preanal papillae. 

 Spicules relatively long and slender, bent at an obtuse angle 

 or almost at right angles. Accessory piece absent. Female 

 genital organs undescribed. Spinneret present. 



Hab. Marine. 



Genotype : L. exilis Marion, 1870. 



Marion, 1870, Ann. Sci. Nat., Paris, Zool., (5) xiii, Art. 14, 

 11 ; and 1870, xiv, Art. I, 8. 



d. Rhabdocoma Cobb, 1920. 



Cuticle thin, unstriated, without bristles except at anterior 

 end. Head not distinct. Three lips, six labial papillae, six 

 jointed cephalic bristles and four cervical bristles present. 

 Lateral organs circular. Pharynx small, with three small, 

 possibly transversely ribbed, thickenings in its wall. Oesoph- 



