238 



SYNOPSIS OF NORTH AMERICAN MYRIAPODA. 



I. canaliculatus. Segments 51. Scuta on the upper surface closely and deeply canali- 

 culate, and furnished with a ring of distant long hairs. 



/. laqueatus. Segments 49. Scuta on the upper surface closely and deeply canaliculate, 

 but not furnished with a ring of hairs. 



I. exiguus."\ Segments 33. 



h. Last scutum not mucronate. 



I. cinere/rons. Brownish, annulate with ash color. Scuta with their upper surface 

 smooth. Segments 34 % — 45 1. 



I. Milesii. Deep brown. Upper surface of scuta nearly smooth ; lower surface closely 

 and deeply canaliculate. Segments 33. 



I. ccerulo-cinctus. Brown, annulate with bluish rings. The surface of the scuta regu- 

 larly but rather distantly canaliculate. Segments 42. 



I. Jtortensis. Brownish, with series of strongly pronounced black dots on each side. 

 Segments 42. Scuta closely canaliculate above and below. 



1. virgatus. Deep brown, with the dorsum lutcous, and ornamented with a black 

 median line. Segments 35. Scuta closely canaliculate above and below. 



I. m.inutus.'f 



I. stigmatosus.^ 



Gen. Sfirobolus. Second scutum produced forwards at the sides so as to abut against 

 the head. 



Upper surface of scuta not canaliculate. 



S. marginatum. Brown, with reddish annuli. Head very abundantly punctate. Seg- 

 ments 53 — 57. 



S. uncigerus. Brown, with reddish annuli. Head rather sparsely punctate. Segments 

 50—53. 



S. spinigerus. Fulvous, with very large greenish maculos. Segments 48. 



Upper surface of scuta canaliculate. 

 S. angusticeps. 



Fam. LYSIOPETALIDiE. 



Sterna atrophied, not coalescent with or united by suture to the scuta. 



Gen. Spirostrephon. 



S. lactarius. Scuta keeled. Segments 59. 



S. caisio annulatus. Scuta not keeled. Segments 32. 



