32 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 89 



family as the free-living genera, because of the close resemblance of 

 their free-living bisexual generation to the free-living forms. Sys- 

 tematically, howrever, this seems to be untenable, because the syn- 

 gonic parasitic generation is widely different, although there are 

 traces of the anterior bulb in some species in this stage also (fig. 69). 

 The free-living generation has the typical rhabditoid esophagus 

 as in other free-living forms ; the parasitic generation has a simpler 

 esophagus without swellings or bulbs, muscular throughout its 

 length. In some species there are traces of the anterior bulb in this 

 stage also (fig. 69). Some species can entirely omit a free-living 

 generation and thereby lose all hints as to their true systematic posi- 

 tion. 



Subfamilies and Genera of the Family Tylenchidae 

 Subfamily Diplogasterinae. 



Genera: Aulolaimus de Man, 1880 (syn. Myctolaimus Cobb, 1920; syn. 

 Cylindrogaster Goodey, 1927) ; Rhabditidoides Rahm, 1930 ; Rhabdi- 

 tolaimus Fuchs, 1915; Neodiplogaster Cobb, 1924 (syn. Tylenchodon 

 Fuchs, 1930); Diplogasteroides de Man, 1912; Lycolaimns Rahm, 

 1930; Loxolaimus Rahm, 1930; Diploscapteroides Rahm, 1930; But- 

 lerius Goodey, 1930; Demaniella Steiner, 1914; Acrostichus Rahm, 

 1930; Diplogaster M. Schuhze, 1859; Peronilaimus Rahm, 1930; 

 Mononchoides Rahm, 1930; Odonto pharynx de Man, 1912; fUngella 

 Cobb, 1928; fScolecophilus Baylis and Daubney, 1922. 

 Subfamily Tylopharynginae. 



Genus: Tylopharynx de Man, 1876. 

 Subfamily Tylenchinae. 



Genera: Aphelenchoides Fischer, 1894 (syn. Chitinaphelenchus Micoletzky, 

 1922; syn. Pathoapheleiichus Cobb, 1927; sg. Schistonchus Cobb, 1927; 

 sg. Parasitaphelenchus Fuchs, 1930) ; Paraphelenchiis Micoletzky, 

 1922; Tylenchulns Cobb, 1913; Nemonchus Cobb, 1913; Heterodera 

 Mueller, 1883 (syn. Meloidogyne Goledi, 1889; syn. Heterobolbus Rail- 

 let, 1896; syn. Caconema Cobb, 1894); Aphelenchus Bastian, 1865 

 (syn. Isonchus Cobb, 191 3) ; Rotylenchus n. g. (type T. robiistus de 

 Man, 1880) ; Pratylenchus n. g. (type T. pratensis de Man, 1880) ; 

 Chitinotylenchns Micoletzky, 1922; Tylenchorhynchus Cobb, 1913; 

 Tylenchus Bastian, 1865; Psilenchus de Man, 1922; Ditylenchus n. g. 

 (type A. dipsaci Kiihn, 1859) ; Anguillulina Gervais et van Beneden, 

 1859; Neotylenchiis Steiner, 1931; lotonchium Cobb, 1920; Hexatylus 

 Goodey, 1926; fMacroposthonia de Man, 1880; Hemicycliophora de 

 Man, 1922; Eutylenchus Cobb, 1913; Ecphyadophora de Man, 1922c; 

 fMyenchus Schuberg and Schroeder, 1904. 

 Subfamily Sphaerulariinae. 



Genera: Aphelenchulus Cobb, 1920; Tylenchinema Goodey, 1930; Allan- 

 tonema Leuckart, 1884; Howardula Cobb, 1921 ; Parasitylenchus Mi- 

 coletzky, 1922; Bradynema Zur Strassen, 1892; Atractonenia Leuck- 

 art, 1887 (syn. Asconema Leuckart, 1886, preocc.) ; Sphaerularia Du- 

 four, 1837. 



