ALAIMIDAE 97 



15. Nuada Southern, 1914. 



Cuticle smooth, extremely thick, without bristles or lateral 

 alae. Head distinct, with four bristles. Lateral organs 

 apparently absent. Oesophagus very long and slender. 

 An accessory piece present. Female genital tubes paired, 

 opposed. 



Hab. Marine. 



Genotype : iV. leptosoma Southern, 1914. 



Southern, 1914, Proc. R. Irish Acad., xxxi, 9. 



16. Leptosomatum Bastian, 1865. 



Syn. Phanoglene Eberth, 1863, nee Nordmann, 1840; 

 Enoplus Eberth, 1863, nee Dujardin, 1845. 



Cuticle unstriated or with longitudinal markings, without 

 bristles. Lateral alae apparently absent. Head with three 

 lips and two crowns of papillae. Oesophagus gradually 

 expanded posteriorly. A pair of ocelli present. Caudal 

 end of male occasionally with supplementary organs or 

 " suckers." An accessory piece present. Testes paired, 

 opposed. Female genital tubes paired, opposed, reflexed. 

 Oviparous. Eggs comparatively numerous, smooth-shelled. 



Hab. Marine. 



Genotype : L. elongatum Bastian, 1865. 



Bastian, 1865, Proc. Roy. Soc. London, xiv, 144; de Man, 

 1893, Mem. Soc. Zool, Paris, vi, 102. 



17. Acoma Steiner, 1916. 



Cuticle unstriated, without bristles. Head distinct, with- 

 out lips but with bristles. Oesophagus expanded gradually 

 behind. Male unknown. Tail of female elongate. Female 

 genital tubes paired, symmetrical, reflexed. Caudal glands 

 rudimentary. Spinneret absent. 



Hab. Marine (Arctic). 



Genotype : A. borealis Steiner, 1916. 



Steiner, 1916, Zool. Jahrb., Sijst., xxxix, 652. 



18. Oxystoraina nom. nov.* 



Syn. Oxi/stoma Biitschli, 1874, nee Dum., 1806. 



Cuticle unstriated, without bristles. Head with fine 

 bristles in genotype. Lateral organs elliptical. Oesophagus 

 slightly expanded behind. Caudal end of male with two 

 preanal bristles. An accessory piece present. Testis single. 



* The name Oxystomina has, we believe, been proposed to replace 

 the preoccupied name Oxystoma. We are unfortunately unable to 

 trace its avithor and date of publication. 



SYN. NEM. H 



