MILLIPEDS OF NORTH AMERICA 181 



Type Locality: San Clemente Island, Los Angeles County, California. 

 Range : Known only from type locality. 



Genus TITSONA Chamberlin 



Titsona Chamberlin, 1912, Ann. Ent. Soc. Amer., vol. 5, p. 160. 

 Generotype : Titsona sima Chamberlin, by original designation. 

 Range: California. 

 Species: One. 



Titsona sima Chamberlin 



Titsona sima Chamberlin, 1912, Ann. Ent. Soc. Amer., vol. 5, p. 161, 

 pi. 10, figs. 4-6.— Loomis, 1943, Bull. Mus. Comp. Zool., vol. 92, No. 

 7, p. 393, figs. 10a, b. 



Type: Mus. Comp. Zool. 



Type Locality: Oroville, Butte County, California. 



Range : Yolo and Butte Counties, California. 



Superorder COLOBOGNATHA 



Colobognatha Brandt, 1834, Oken's Isis, p. 704. — ^Latzel, 1884, Myr. Ost.- 

 Ung. Monarch, vol. 2, p. 56.— Bollman, 1893, U. S. Nat. Mus. Bull. 46, 

 p. 154— Cook and Loomis, 1928, Proc. U. S. Nat. Mus., vol. 72, 

 art 18, p. 4. 



Siphonizantia Brandt, 1837, Bull. Sci. Acad. Sci. Saint-Petersbourg, vol. 1 

 (1836, No. 23), p. 178. 



Sugentia Wood, 1869, Trans. Amer. Philos. Soc, vol. 13, p. 248. 



KEY TO ORDERS OF COLOBOGNATHA 



1. Gnathochilarium having the usual parts represented in millipeds; tergites with a 



distinctly impressed median sulcus Platydesmida (p. 181) 



2. Gnathochilarium represented by a single triangular plate, or the divisions at most in- 



distinctly indicated; tergites without an impressed median sulcus. 



POLYZONHDA (p. 185) 



Order PLATYDESMIDA 



Platydesmiens Saussure, 1860, Mem. Soc. Phys. Hist. Nat. Geneve, vol. 15, 



p. 83. 

 Platydesmia (in part) + Dolistenia Latzel, 1884, Myr. Ost.-Ung. Monarch., 



vol. 2, p. 356. 

 Platydesmini Pooock, 1887, Ann. Mag. Nat. Hist., ser. 5, vol. 20, p. 225. 

 Platydesminae + Andrognathinae Bollman, 1893, U. S. Nat. Mus. Bull. 



46, p. 154. 



Family ANDROGNATHIDAE Cope 



Andrognathidae Cope, 1869, Proc. Amer. Philos. Soc, vol. 11, p. 182. — 

 Cook and Loomis, 1928, Proc. U. S. Nat. Mus., vol. 72, art. 18, p. 18. 



