THE MYRIAPODA OF NORTH AMERICA. 187 



of the antennae. Anal segment . Anal valves small, smooth; 



anal scale absent. Lateral carince . Repngnatorial pore be- 

 ginning at the fifth segment. 



Polyzoiiium rosalbum. 



Petaserpes rosalbus Cope. Trans. Amer. Ent. Soc., 65, 1870 (Cumberland Mountains, 



Tenn.). 

 Bexaglena eryptocepliala McXeill. I 'roc. U. S. Xat. Mas. ,328, 1887 (Bloomington, Ind.). 



OCTOGLENA. 



1864. Octoglena Wood. Proc. Phila. Acad. Nat. Sci., 186 (birirgatu). 



If we can trust the figures of Wood showing the head and a few seg- 

 ments of Octoglena bivirgata, this genus differs from Polyzonium by hav- 

 ing the first segments inarginate and not concealing the ocelli. 



If his figures are not trustworthy Octoglena is equal to Polyzonium. 



This genus contains the following species: 



Octoglena bivirgata. 



Octiujli na bicirgahi Wood. Proc. Phila. Acad. Xat. Sri., 186, 1864 (Georgia); Wood, 

 Trans. Amor. Phil. Sor.. 229, 1865. 



I>. PLATYDESM IN.*]. 



ISGO.Plalydesmii Sanssure. Myr. Mex.. 83. 



1872. Pl<tii/ilcx>iiia Humbert and Saussure. Miss. sci. Mex., vi, 99. 

 1884. Dolistenialj&tzeL Myr. Ost.-Uugar. Monarch., ir, 362. 

 1887. Plalydi-smini Porork. Ann. and Mag. Nat. Hist., 225. 



of the genera of Platydesmince. 



a. Body narrow, filiform ; meutuni rectangular ; hypostoma not well developed; anal 

 scale absent; segments not tuberculate. 



1>. Fifth segment normal, pores not carried on a pedicel DOLISTEXUS. 



bl>. Lateral rarina) of fifth segment large, deeply sinuate, anterior lobe directed 

 forwards and bearing the repugnatorial pore, which is raised on a short 

 pedicel; other pores on a pedicel but opening on the posterior half of seg- 

 ments AXDROGXATHUS. III. 



ta. Body wide, depressed; iiinitum hammer-shaped; hypostonia well developed; 

 anal scale present; segments tulx-rcnlate Pi..vTVi>EsMrs. IV. 



ANDROGNATHUS COPK. 

 1869. Andrognathus Cope. Proc. Amer. Phil. Soc., 182 (corticarius). 



Body narrow, fiftform, convex above and below, covered with numer- 

 ous short hairs. Head not rostrate (mouth parts not adapted tor suck- 

 ing), not concealed by first dorsal plute, densely pilose. Antenna 1 

 clavate, short. Ocelli absent, (iiiathochilarium xvell developed, stipes 

 acuminate, destitute of mola and teeth; hypostonia rectangular: cardo 

 rather long and narrow, triangular; nientum rectangular; piomentum 

 elongate-ovate; lingual plates, acuminate, separate, destitute of lobes. 

 Dorsal plates medianly silicate, not tuberculate. First dorsal plate 



