18 PEOCBEDIlSrGS OP THE NATIONAL MUSEUM vol.72 



Genus POLYZONIUM Brandt 



POLYZONIUM BIVIRGATUM (Wood) 



Octoglena bivirgata Wood, Proc. Plaila. Acad. Nat. Sci., p. 186, 1864. 

 Petaserpes rosalhus Cope, Trans. Amer. Ent. Soc, vol. 3, p. 65, 1870. 

 Hexaglena crpptocephala McNeill, Proc. U. S. Nat. Mus., vol. 10, p. 328, 1887. 

 Polyzonium rosaWum Bollman, and others. 



This species has long been called Polyzoniv/m rosalbum (Cope) but 

 that it resembled Octoglena tivirgata Wood has been known for 



many years and the likelihood of its 

 being a synonym of Mvirgata was also 

 considered on the basis of Wood's draw- 

 ings being poorly made and failing to 

 show the true relation and shape of the 

 head and anterior segments. Since no 

 material has ever been found to prove 



PIG. 4.-P0LYZ0NIUM BIVIRGATUM. ^^^ distiuctncss of the two spccics, It 

 latekal mabgins and eepug- seems best to assume that rosaTbwm is a 

 IT^lto r^^^ ""^ segments synomyn of hivirgatum, which is the 



older name. 

 The species has been reported from Georgia, Tennessee, New York, 

 Indiana, and Michigan and may be expected from many other of the 

 Eastern States. A peculiarity of Polyzordwm is that the repugna- 

 torial secretion has a camphor-like odor, but whether this is true of 

 other members of the family is not known. ^ 



Family ANDROGNATHIDAE 



The separation of this family from the tropical Platydesmidae is 

 based on the structure of the sterna. The Andrognathidae have the 

 basal joints of the legs almost in contact, but separated by a peculiar 

 fungiform structure, while the Platydesmidae have the legs separated 

 by broad sterna and are without the inter coxal projections. 



analytical key to geneka op andrognathidae 



Repugnatorial pores elevated on a short stalk or pedicel; fifth segment with 

 lateral carinae deeply emarginate, bilobed ; anal scale absent Andrognathns.. 



Pores not elevated on pedicels ; fifth segment not different from adjacent seg- 

 ments ; anal scale present. 



Body very slender, attaining a length more than twenty times the width; 

 number of segments very large, sometimes more than 100 ; dorsum not tuber- 

 culate, evenly convex Mitocybe, new genus. 



Body broader, less than fifteen times as long as wide; segments less than 70; 

 dorsum tuberculate; lateral carinae longitudinal or depressed. 



Body about twelve times as long as broad ; loosely jointed, with anterior sub- 

 segments partly exposed ; first segment not tuberculate, without lateral 



^ Cook, O. P. Camphor secreted by an animal. Science, new ser., vol. 12, pp. 516-521, 

 1900. 



