INTRODUCTION d 



its position as correct down to the present, although the name has not been 

 in general use. 



In 1840 Brandt divided his order Myriapoda into two subdivisions: the 

 Gnathogena — for the Chilopoda and most of the Diplopoda, and the Sugen- 

 tia — corresponding precisely to the diplopod group now commonly termed 

 the Colobognatha. Gervais in 1837 made but two divisions of the Chilog- 

 natha, the Oniscoidea and the Juloidea. In 1847 he replaced the term 

 Chilognatha with the name Diplopoda of Blainville, and dropped his original 

 primary subdivisions, recognizing the following families: Polyxenidae, Glo- 

 meridae, Julidae, and Polyzoniidae. The English zoologist Newport (1844, 

 "List of the . . . Myriapoda in . . . British Museum") followed Brandt as 

 to the divisions Pentazonia and Monozonia, but introduced a division Bizonia 

 to embrace the Brandtian Trizonia and Sugentia. C. L. Koch (1847) ignored 

 the primary divisions above the level of family, describing under the Chi- 

 lognatha numerous new species and genera in the families Polyxenidae, 

 Glomeridae, Sphaeriotheridae, Julidae, Blaniulidae, Chordeumidae, Poly- 

 desmidae, and Polyzoniidae. 



C. S. Rafinesque, the first American worker to describe our native 

 millipeds, in 1820 named four new genera and species in his "Annals 

 of Nature;" in 1821 Thomas Say noted ten species as occurring in the 

 United States, and scattered accounts of others were added by Brandt, 

 Koch, Gervais, and Saussure; but the real foundation for the study of 

 North American diplopods was laid by Horatio C. Wood in a series of 

 papers appearing from 1861 to 1867, the most important of these being the 

 "Myriopoda of North America" (1865), in which he described the forms 

 known at that time to occur in this country. The total recognized by Wood 

 comprised 18 genera and 92 species, of which 10 genera (including sub- 

 genera) and 41 species are diplopods, the remaining are chilopods. In his 

 general arrangement of diplopods, Wood adopted as suborders the Pentazonia 

 and Sugentia set up by Brandt, but introduced as a third suborder the Strongy- 

 lia, under which he placed the millipeds arranged by Brandt under Trizonia 

 and Monozonia. His classification was as follows: 



Order Chilognatha 

 Suborder Pentazonia 

 Families: 

 Glomeridae 

 Sphaeriotheridae 

 Suborder Strongylia 

 Families: 

 Polyxenidae 

 Polydesmidae 

 Julidae 

 Lysiopetalidae 

 Suborder Sugentia 

 Families: 

 Polyzoniidae 

 Siphonophoridae 



