Rev 10/99 Class Chromadorea 1. pore-like or slit-like amphid
apertures, always labial. 2. deirids present in some near nerve
ring. 3. phasmids present, generally posterior. 4. no hypodermal
glands, but hypodermal cells are multinucleate. 5. excretory
system tubular. 6. no caudal glands. 7. male generally with a
single testis. 8. caudal alae common. 9. male with paired
preanal supplement glands in two sublateral rows. 10. sensory
papillae cephalic only, although may be caudal papillae in
males. 11. esophagus varies but has 3 esophageal glands. 12.
almost exclusively terrestrial, rarely freshwater or marine.
Sub-class: Rhabditia - no stomal armature. three-part esophagus
has corpus, isthmus and metacorpus. Tri-lobed chamber in
terminal metacorpus. Orders: 1. Rhabditida - microbivores in
soil; vertebrate and invertebrate parasites. males with delicate
rays in caudal alae. Rhabditis, Caenorhabditis, Cephalobus,
Steinernema, Heterorhabditis, Acrobeles. 2. Strongylida - adults
are vertebrate parasites; juveniles fe