APPENDIX TO CHAP TEE V 70 



Anus in ultimate segment ; body without 



bunches of hairs, 

 d. Mandibles not rudimentary ; mouth 



parts not suctorial. 

 d\. Segments 80 or more. 



e\. Anal segment produced into 



a spine .... Julidce 



(Ex. Julus) 



e 2 . Anal segments produced into 

 2 slender papilhe, or uni- 

 dentate .... Craspedosomidce 

 d-2. Segments 19 or 20 ... Polydesmidce 



(Ex. Polydesmus) 

 Co. Mandibles rudimentary, mouth parts 



reduced Polyzoniidw 



KEY TO COMMONER SPECIES OF THE GENUS LITHOBIUS 



a\. Posterior angles of none of dorsal plates pro- 

 duced ; pores on coxae uniseriate. 

 b\. Anal feet armed with 1 spine ; posterior coxae 

 unarmed ; spines of first pair of feet, 2, 2, 

 2-2, 3, 2 (Central States) . . . bilabiatits 



b-2. Anal feet armed with 3 spines ; coxse with 

 indistinct spine ; spines of first pair feet, 

 2, 3, 2 (Central States) .... cardinalis 



2 . Posterior angle of the 9, 11, 13 dorsal plates pro- 

 duced ; antennae, 33-43 joints (eastern U.S.) forficatus 

 3 . Posterior angle of the 7, 9, 11, 13 dorsal plates 

 produced ; 31-38 joints of antennae (southern 

 U.S.) . . . . . . . . spinipes 



4 . Posterior angle of the 6, 7, 9, 11, 13 dorsal plates 

 produced ; joints of antennae, 14.-23 (eastern 

 U.S.) multidentatus 



