MILLIPEDS OF NORTH AMERICA 85 



Coelocheta + Merocheta Cook, 1896, Amer. Nat., vol. 30, p. 683.— SU- 

 vestri, 1897, Ann. Mus. Civ. Stor. Nat. Genova, ser. 2, vol. 18, p. 3. 



Nematophora Verhoeff, 1913, Zool. Anz., vol. 43, p. 52. — Attems, 1926, 

 in Kiikenthal-Krumbach, Handbiich der Zoologie, vol. 4, p. 154. — 

 Schubart, 1945, Arq. Mus. Nac. Brasil, vol. 38, p. 8. 



Chordeumida Chamberlin, 1943, Bull. Univ. Utah, biol. ser., vol. 8, No. 3, 

 pp. 5, 34. 



The four suborders into which this order is divided may be distinguished 

 by means of the key given below. Of them, no representative of the Stem- 

 miulidea has yet been found within our limits. 



KEY TO THE SUBORDERS OF CHORDEUMIDA 



1. Body segments of adults 39 or more; repugnatorial pores present 2 



Body segments not more than 32; no repugnatorial pores 3 



2. Only 1 or 2 ocelli on each side ; body dorsoventrally compressed ; segments with fine 



striae Stemmiulidea 



Ocelli numerous, in a triangular patch; body rounded; segments with pronounced 

 longitudinal crests and enlarged poriferous knobs . . . Lysiopetalidea (p. 108) 



3. Metazonites with high carinae over middorsal region; collum large, hoodlike, partly 



concealing the head; anal segment trilobed Striariidea (p. 115) 



Metazonites without longitudinal carinae or ridges; collum smaller, never hoodlike, 

 head usually exposed; anal segment entire Chordeumidea (p. 85) 



Suborder CHORDEUMIDEA 



Chordeumidae (in part) Koch, 1847, in Krit. Rev. Insect. Deutschlands, 



vol. 3, p. 49. 

 Chordeumoidea Cook, 1899, Proc. U. S. Nat. Mus., vol. 21, p. 669.— Attems, 



1926, in Kiikenthal-Krumbach, Handbuch der Zoologie, vol. 4, p. 154. 

 Ascospermophora Verhoeff, 1913, Zool. Anz., vol. 43, p. 53. 



KEY TO NORTH AMERICAN FAMILIES OF CHORDEUMIDEA 



1. Body composed of 20 or 26 segments 2 



Body composed of 28, 30, or 32 segments 3 



2. Segments 20; tergites not produced laterally into paranota (lateral carinae of older 



authors) Ergethidae (p. 105) 



Segments 26; tergites with numerous short dorsal crests and prominent paranota. 



Brannerhdae (p. 86) 



3. Telopodite of second pair of legs of the seventh segment of males much thickened, 



often clavate, the second joint often forming a distinct angle with the coxa, the 



latter with a conspicuous inner process 4 



Second legpair of seventh segment in males never clavately thickened as described 

 above, and not forming a distinct angle with the coxa, which has no inner process . 6 



4. Gnathochilarium undivided, no promentum set o£E . . . . Conotylidae (p. 97) 

 Gnathochilarium with a promentum 5 



5. Tergites with setigerous keels, the sides of segments at most vaguely striate. 



Underwood iidae (p. 107) 

 Tergites without setigerous keels, the sides with pronounced lateral striae 



Caseyidae (p. 87) 



