10. Posterior angles of two dorsal plates produced (11 ^ 13) 



Hemihthohius Stuxberg 

 Posterior angles of three dorsal plates produced (9, 11 & 13) 

 Lithohius Leach 



11. With twenty-one to twenty-three pairs of legs; with or without eyes — 



Scolopendromorpha (or Scolopendridae) 12. 



With thirty -one or more pairs of legs in the adult; without eyes — 



Geophilomorpha (or Geophilidae) 15. 



12. With eyes (four ocelli) 



Scolopendra Linn. 

 Eyes absent or with only one ocellus 13. 



1 3 . With twenty-three pairs of legs 



Otocryptops Haase 

 (Scolopocryptops Newport) 

 With twenty-one pairs of legs 14. 



14. Anal legs much shortened and thickened 



Theatops Newport 

 Anal legs longer 



Cryptops Leach 



15. Dorsal plates not furrowed 16. 

 Dorsal plates with two lengthwise furrows 17. 



16. Head plate narrowed anteriorly 



Linotaenia Koch 

 Head plate narrowed posteriorly 

 Dicellophilus Cook 



17. Ventral pores scattered 



Gnathomerium Ribaut 

 Ventral pores in definite clusters on the ventral plates, or absent 18. 



18. Ventral pores on the middle of the ventral plates, or absent 19. 

 Ventral pores on the rear of the ventral plates 20. 



19. No ventral pores 



Escaryus Cook 6? Collins 

 With ventral pores on the center of the ventral plates 

 Schendyla Bergs. 



20. Last ventral plate narrow 



Pachymerium Koch 

 Last ventral plate usually wide 21. 



21. With prehensile feet extending beyond the head 



Arenophilus Chamberlin 

 Prehensile feet not extending beyond the head 

 Geophilus Leach 



GENERAL REFERENCES 



Bollman, C. H. 1893. The Myriapoda of North America. (Edited by L. M. 

 Underwood.) Bull. U. S. Nat. Museum, No. 46. 



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