154 BULLETIN 46, UNITED STATES NATIONAL MUSEUM. 



Superorder I.— CHILOGNATHA. 



This division is divisible into tlie following orders : 



a. Copulatory organs of male formed, by a transformation of one or both pairs of 



legs of seventh segment ; alimentary tract straight ; tracheae simple. 



b. Mandibles and gnathochilarium rudimentary; labruni sinuate; mouth parts 



more or less suctatorial Colobogxatha.- — I. 



bb. Mandibles and gnathochilarium not rudimentary; labrum tridentate; mouth 



parts not suctatorial Helminthomorpha. — II. -As -* 



aa. Copulatory organs of male formed by accessory pairs of legs, situated at the pos- 

 terior part of body ; labrum sinuate or unidentate ; alimentary tract bent ; 

 trachea? branched Oxiscomorpha. — III. I 



Order I.-COLOBOGNATHA. 



This order contains the following" family: 



Family L— POLYZONIIDJE. 



Analysis of the subfamilies of Polyzoniidw. 



a. Gnathochilarium represented by an acute triangular plate; dorsal plates not sili- 

 cate; lateral carinas not well developed. 

 b. Body filiform, pilose ; ocelli absent; anal scale present; antenna? strongly cla- 



vate; mouth parts strongly suctatorial Sipiioxopiiorix.e. — I. 



bb. Body wide and depressed, not pilose; ocelli present; anal scale absent; anten- 

 nae not strongly clavate; mouth parts less suctatorial. 



P OLYZOXIIX.E.— II. 



aa. Gnathochilarium well developed, subsimilar to that of the Jiilidw; dorsal plates 



sulcate and covered with numerous short stiff hairs; lateral carina? well 



developed, 

 c. Body filiform; mentum rectangular; hypostoma not well developed; anal 



scale absent; segments not tuberculate Axdrogxathin.e. — III. 



cc. Body wide, depressed ; mentum hammer-shaped; hypostoma well developed ; 



anal scale present ; segments tuberculate Ptatydesaiix.e. — IV. 



Subfamily I. — Siphonophoein^e. 



Includes the genus Siphonophora Brandt, which is distinguished by 

 the characters given for the subfamily. 



Subfamily II. — Polyzoniin^e. 



Analysis of the genera of Polyzoniina}.* 



a. Anterior margin of first dorsal plate emarginate, not concealing the ocelli. 



Octoglena Wood. 



aa. Anterior margin of first dorsal plate rounded, advanced forward to the base of 



the antenna?, concealing nearly all the ocelli PoLYZOXiUMt Brandt. 



* Slphonotus Brandt. Bull. Sc. Acad. St. Petersb., 1836. This genus probably 

 belongs to this subfamily. It has two ocelli as in Polyzonium, but the antennas are 

 sub-similar in form to that of Geophilus. 



t Polyzonium (=Platyiilus Gervais, = Lviosoma Victor, = Peiaserpes Cope, = Pies- 

 todesmus Fanzago, =Hinulisoma Fanzago, = Hexaylena McNeill. Proc. U. S. Nat. 

 Mus., 328, 1887). 



