Order ItHABDITIDA Chitwood, 1933 

 (Key to the suborders from Cliitwood, 1950) 



1. Lips 3> 2 or 0; corona radiata absent; adults with all gradations 

 from rhabditoid to cylindrical esophagus; female reproductive 

 system usually complex, vagina usually heavily muscled; bursa, if 

 present, with papillae; spicules 2, 1 or 



ASCARIDIM Skrjabin, 1910 P. 3 



2. Lips 6, 3 or 0; corona radiata present or absent; feinale reproductive 

 system usually complex, vagina often heavily muscled; adult with 

 clavate type esophagus; bursa usually containing well-developed 

 muscles forming the true or strongylatid bursa 

 STFONGYLINA Pailliet and Henry, 1913 P. U 



3. Lips 6, 3) 2 or 0; corona radiata absent; spear present or absent; 

 female reproductive system relatively simple, vagina usually trans- 

 verse and usually not heavily muscled; esoohagus may or may not be 

 terminated by a valved bulb; bursa, if present, containing papillae 

 rather than "rays"; spicules 2 RHABDITINA. Chit., 1935 P. U 



Suborder ASCARIDINA Skrjabin, 1915 

 (Key to the superfamily from Chitvrood, 1950) 



1. Stoma usually surrounded by esophageal tissue and collapsed (except) 

 Subulurinae); deirids present; mostly large, stout worms; males with 

 2 spicules 



ASCARIDOrDEA Railliet and Henry, 1915 



2. Stoma cylindroid or short, not siirroimded by esophageal tissue; 

 deirids absent; mostly small or medium-sized transparent worms; males 

 with 1 or 2 spicules OXYUROIDt^IA Railliet, 1905 



