11;^ 



Genus Aporcelaimus Th. & Swang., 1936 

 (Key to the species including material from Thorne & Swanger, 1936) 



1. Spear aperture continuous 2 



Spear apertiire angular 17 



2. Lips obscure or amalgamated 3 



Lips prominent, conspicuous It 



3. Length 6.1 - 6.U mm; supplements 23 . . paraspiralis Th. & Swang., 1936 

 Length 1.7 - 2.3 mm; supplements 8-9 minor Loos, I9k^ 



U. Spear aperture about equal to length of spear 5 



Spear aperture distinctly shorter than length of spear 7 



5. Tail distinctly conical, elongate; length 3.3 mm; males unknown 



conicaudatus Altherr, 1953 



Tail round or subconoid; length U.7 - 6.9 mmj male known 6 



6. Cuticle near head in 3 layers; length 5»8 - 6.9 mm 



. regius (de Man, 1876) 



Cuticle near head in 2 layers; length U.7 - U.9 mm 

 pachydermus Thorne, 1937 



7. Tail efilated, digitate 8 



Tail round or subconoid, not digitate 10 



8. Length 5.0 mmj female unknown cobbi Thome, 1937 



Length less than 3.5mm 9 



9. Tail with two caudal papillae gerlachi Meyl, 1956 



Tail with four caudal papillae digitalis Loos, 19149 



10, Female pre-rectum U-5 times length of rectum; lips lower than usual 



for the genus spiralis (Cobb, 1893) 



Female pre-rectum 3 times length of rectum or shorter; lips high. . 11 



11, Length 5.0 - 8.0 mm 12 



Length U.U mm or less 13 



12. Cuticle near head with a thin outer layer 



eurydurys (Ditlevsen, 1911) Th. & Swang., 1956 



Cuticle near head in three distinct layers 

 americanus Th. & Swang., 1936 



13. Expanded basal portion of esophagus about one- third as long as neck 



..... ferrugineus Lordello, 1953 



Expanded basal portion of esophai^us frcxn one-half to two-thirds as 

 long as neck ll; 



Ik. Length l.H mm; tail uniformly conoid, . . . paraconicaudatus Meyl, 1956 

 Length 3.O - I4.U mm; tail obtusely conoid l5 



