— 147— 



Family i. POLYXENIDAE Cray and Jones. 

 This family contains the single genus Polvxenus Latr , of which we 

 have one species /'.y"t/j«t7^Az/wj- Say, distributed from Massachusetts to 

 Georgia. 



Family 2. POLYZONIDAE Gcrvais. 

 This family contains four American genera witli live species; the 

 genera may be distinguished as follows: 



A. - Sixth and seventh joints of antenna; confluent with the fifth and with it forming 



a club; body segments 56 Andrognathus Cope.* i sp. 



Joints of antennae normal, not forming a ckib B. 



B. — Eyes wanting; rostrum shorter than tlie antennas. . . .Biachycybe Wo^.d.** 2 sp. 



Eyes present, conspicuous C. 



C. —Eyes 8; body segments about 45 Octoglena Wood, i sp. 



Eyes 2; antennae large and stout; body segments 50 53 



Pet.aserpes Cope, i >p. 

 Family s. POLYDESMIDAE Leach. 

 The Polydesmidae'o'i this country have all been described under 

 Polydesmus Latr. f of which twenty-one species are recorded. Strongyhi- 

 scma Brandt, Fontaria Gray and perhaps other groups ranked as sub- 

 genera by Wood, will take generic rank; until, however, a careful study 

 of the types can be made it will be best to leave the species in the orig- 

 inal genus under which they have been described. 



Family 4. CHORDEUMIDAE C. Koch. 

 With some hesitation I place in this family most of the forms hitherto 

 ranked -xi Lysiopetalidae by American writers. In this I follow Dr. Latzel 

 whose important work has been noticed above. In a note on the American 

 Chordeumidaf\'\ he unites Scoterpes Cope and Zygonopus R)'der and places 

 them as a subgenus of Craspedosoma Leach-Rawlins. Trkhopetalum 

 Harger he also regards as forming part of Craspedosoma, and Pseudotrtmia 

 Cope, he would place near the same j;enus Crypiotrichus Packard, he 

 places near Campodes Koch. The form of '' Polydesmus with eyes" re- 

 cently described by Packard, | Latzel^ states is properly one of the 



* Forming according to Cope (Froc. Amer. Philos. Soc. XI, 182) the type of a 

 new family Andrognathidw. 



** Latzel unites Brachycybe Wood with Plntydesmus Lucas. The latter genus 

 has priority. 



t An apparent exception is Stenonia hisjnda Sager, Proc. Phila. Acad. VIII, 

 109 (1856). This undoubtedly belongs to Polydesmus though the description is very 

 imperfect. 



tt Die Myriapoden der Oest.-Ungar. Monarchic, II, pp. 213 — 214 (1884). 



t American Naturalist XVII, 428 (1883). 

 II Latzel, loc. cit. p. 125, note. 



