424 GENERAL BIOLOGY 



Order 27. Diptera ( ) 



Order 28. Suctoria ( ) 



Subclass 11. Rhynchota ( ) 



Order 29. Homoptera ( ) 



Order 30. Hemiptera ( ) 



GROUPS OF INVERTEBRATES OF MORE OR LESS UNCER- 

 TAIN SYSTEMATIC POSITION 



Group 1. Mesozoa ) 



Group 2. Nemertinea ( ) 



Group 3. Nematomorpha ( ) 



Group 4. Acanthocephala ( ) 



Group 5. Chaetognatha ( ) 



Group 6. Rotifera ( ) 



Group 7. Bryozoa ( ) 



Group 8. Phoronidea ( ) 



Group 9. Brachiopoda ( ) 



Group 10. Gephyrea ( ) 



PHYLUM XI. CHORDATA 



Subphylum I. Cephalochorda or Adelochorda ( ) 



Subphylum II. Urochordata or Tunicata ( ) 



Order 1. Larvacea ( ) 



Order 2. Ascidiacea ( ) 



Order 3. Thaliacea ( ) 



Subphylum III. Hemichordata ( ) 



Order 1. Enteropneusta ( ) 



Order 2. Pterobranchiata ( ) 



Order 3. Phoronidia ( ) 



Subphylum IV. Vertebrata or Craniata ( ) 



Class I. Cyclostomata ( ) 



Subclass 1. Myxinoidea ( ) 



Subclass 2. Petromyzontia ( ) 



Class II. Pisces or Gnathostomata ( ) 



Subclass 1. Elasmobranchii ( ) 



Order 1. Plagiostomi ( ) 



Suborder I. Selachii ( ) 



Suborder II. Batoidei ( ) 



Order 2. Holocephali ( ) 



