244 APPENDIX TO NEIVIATODA 



figures suggest that the " protrusible oesophageal tube " was 

 a moulted cuticle, carrying with it the oesophageal lining. 



7. Choronema Cobb, 1920. 



Cutical thin, finely striated, without bristles. Lateral 

 alae present. Head not distinct, without lips, papillae or 

 bristles. Lateral organs uncertain. Pharynx " absent or 

 obscure." Oesophagus cylindroid, slightly swollen behind. 

 Tail with two sublateral papillae. Spinneret absent. Descrip- 

 tion based on an immature, moulting specimen. 



Hab. Soil. 



Genotype : C. simplex Cobb, 1920. 



Cobb, 1920, Contr. Sci. NematoL, ix, 238 and key ; Micoletzky, 

 1922, Arch. J. Naturg., Abt. A, Ixxxvii, 570. 



Micoletzky (1922) believes C. sirnplex to be closely related 

 to a larval Tylenchiis described by him, and it seems possible 

 that Choronema should be regarded as a synonym of Anguil- 

 lulina. Cobb, however, compares it with " a deteriorated 

 Cephalobus or Diplogaster.'' 



8. Cystoopsis Wagner, 1867. 



Male very small, cylindrical. Female with anterior portion 

 of body cylindrical and posterior portion swollen into a globular 

 sac. Cuticle finely striated. Mouth surrounded by a low 

 cuticular ring. Buccal cavity fumiel-shaped. Alimentary 

 canal without posterior opening, the cylindrical oesophagus 

 ending in a blind sac or bladder-like enlargement. Caudal end 

 of male rounded, with a tubular terminal projection upon 

 which the genital tube appears to open, and which is regarded 

 by V. Linstow as a '" penis." Spicules absent. Vvdva in the 

 slender anterior portion of the body, near the head. Female 

 genital tube apparently single. Oviparous. Egg-shells thick, 

 with polar plugs. Eggs embryonated when laid. 



Hab. Subcutaneous nodules in a Fish {Acipenser). 

 Genotype : C. acipenseris Wagner, 1867. 



Wagner, 1867, Arb. 1. Kongr. russ. Naturf., Silz. zool. Sekt., 

 6 [quoted by v. Linstow] ; Zykov, 1902, Biol. Centralbl., 

 Leipzig, xxii, 229 ; v. Linstow, 1904, Arch.f. Naturg., Ixx, i, 297. 



9. Dikentrocephalus Wcdl, 1855. 



Syn. Dicentrocep)halus Diesing, 1861. 



Small worms with the head-end truncate and having two 

 rounded lips, between which are two processes which, when 

 extruded, appear as a fused " stylet." Oesophagus short. 

 Posterior end rounded, with two distinct lateral ridges and 

 four papillae. 



