434 



cobb: new nematode genera 



KEY AKD CHAHACTERS 

 She iollowlng characters are common to all known species of these twenty- 

 Six proposed new genera: pharynx present, all known males have two equal spicula; 

 no bursa, except in Eutylenchus . Diploseapter . ana Isonehus : no eye-spots. 



MOUTH ARMED WITH AN AXIAL^ no spinneret ; quite naked,(Exe.2 & 3). 

 Spear bulbed at base. 1-3^ of body-length(Exo.l&4) ;no amphidsl Exc .l&G) 

 Canal Dorylaimoid *amphids stirrupform;Hd .papillate, -rf- '8' •** 

 Canal Tylenchoid ;** spear 6-80$S of body-length in lota- 

 Cephalic setae four; striae coarse; renette present. 

 Bursa none;skin grooved lengthwise; no lips. -rf -9 

 Bursa ribless; skin not grooved; lips 3. -rf 



Cephalic setae none;renette present .doubtful in 6&7. 

 Striae huge .retrorse; oesophageal bulbs faint. -rf -9 

 Striae fine! or none in 6); has oesophageal swellings. 

 Head somewhat beaklike, lipless; renette present. ;rf -5- 

 Head as usual, not beaklike; renette( pore)present . 

 Lips papillate; spear diffuse; amphids slitlike, -rf? '$'' 

 Lip-region helmeted ; spear obvious ; no lips or papillae. =cf -9- 

 Spear plain . amphids stirrupf orm(unknown in 8&ll);no renette(Exc .in 8 

 Canal Tylenchoid ;** striae coarse; lipless;bursa ribbed. -cT -? 

 Canal Dorylaimoid;* striae finelor 0);lips 6(0 in 14 ) ,bi-papillate. 

 Vestibule broad; spear acute ,cylindroid. 

 Lip region discoid, much expanded. '9' 



Lip region not discoid;(f's with 2 anal papillae side by side. 

 Labial ribs uniform, not grouped;llps united. -J- '9' 

 Labial ribs in groups, lips distinct. '9' 



Vestibule small or none. 



Lip region protrudable. -rf- '9' 



Lip region not protrudable. 

 Spear conoid, short, toothlike. 



Spear slender, very long, 40% of neck, flexible. -<S '9"' 

 MOUTH WiTHOUT SPEAR- Striated( Exc.6&26 ) .Labiate(Exc. 21). 

 Pharynx armed with a tooth, conoid or pyramidal! Exc. 16 ) . 

 Tooth spearlike;no renette or spinneret;no setae( Exc.l5&17 ) . 

 Alimentary canal Dorylaimoid ;**lips bi-papillate. 

 Alimentary canal Tylenchoid,* lips mono-papillate. 'i'' 

 Tooth not spearlike, obscure in 15. 

 Striae resolvable into elements. 

 Oesophagus bulbed; has setae, spinneret & renette. '9' 

 Oesophagus plain;no setae or renette. '9 



Striae not further resolvable; spinneret present;lips papillate. 



NEW 

 GENERA 

 XIPHINEMA 



ATYLEHCHUS 

 EUTYLEKCHUS 



IOTA 



TYLEUCHORHYNCHUS 



ARCHIONCHUS 

 NEMOBCHOS 



ISONCHUS 8 



DISCOLAIMUS 



ACTINOLAIMUS 

 ANTHOLAIMQS 



10 

 11 



DORYLAIMELLUS 12 



NYGOLAIMUS 

 TRICHODORA 



NYGOLAIMUS 

 ARCHIOKCHUS 



ACHROMAPORA 

 CRYPTONCHUS 



13 

 14 



13 

 6 



15 

 16 



Cephalic setae ten;renette unknown. 

 Cephalic setae none. 

 Lips bi-papillate;amphids stirrupform;no renette. 

 Lips not bi-papiliate;amphids elliptical;no renette. 

 Pharynx unarmed ,'prismold{Exc.24&26); spinneret ( Exc.20&23) . 

 Meek Rhabditoid , i .e .with median & cardiac, bulbs. 

 Renette present ; "diggers"on Hd.;no spinneret. *rf 

 Renette unknown; no "diggers"; spinneret present. -rf- 

 Beck not Rhabditoid ,( no median bulb) 

 Head with empty expansions or bladders;has renette. 

 Head without chitinous bladders. 

 Amphids none; skin not striated;renette unknown. 

 Amphids and spinneret present, fine striae, or none. 

 Cardiac bulb present, amphids not spiral:has renette. 

 Cardiac bulb none or rudimentary. 

 Amphids spiral , renette present, lips 3, faint , flat . 

 Amphids transv. slits; no renette;lips 3, massive, conoid 



'9' 



'9 

 '9 



'9^ 

 '9^ 



'9 

 '9 



NANNONCHUS 17 



OIONCHUS 

 UDONCHUS 



DIPLOSCAPTER 

 HALIPLECTU3 



18 



19 



20 

 21 



WILSONEMA 22 



GYMNOLAIMtlS 23 



CHRONOGASTER 24 



ANONCHDS 25 

 TRISCHI STOMA 26 



* Oesophagus without bulbs, posterior portion much the wider; intestine with a 



distinct short segment in front of the rectum,- the pre-rectum 



**Oesophagns with median and v/ith cardiac bulbs, intestine without pre-rectum. 



*** '9'* .ovaries two and reflexed. 



-9-, ovaries two and outstretched. 



'8 .ovary single, in front £; reflexed. 



-9 .ovary single. In front & outstretched- 



-rf-, testes two and outstretched. 



-d .testis single. in front & outstretched. 



