THE MVKIAl'UDA OF NORTH AMERICA. 187 



of tlie aiiteniKT. Anal segment . Anal valvos small, smooth; 



anal scale absent. Lateral carina' . Kejuignatorial pore be- 

 ginning at the fifth segment. 



Polyzonium rosalbum. 



PetuHerpes romlbua i'o\M-. 'J'raiis. Aiiht. Ent. Soc, ft"), 1870 (t,'ninl>»'rland MoiintuinH, 



Tonn.). 

 Ihxuijhna crypfoirphnhi McNeill. I'iik-,. U. S. Nut. Mns., ;}28, 1SS7 (Hlooiuiii'jton, Tint.). 



OCTOGLENA. 



lH&i.—0<to(fhiiu W.xxl. Proc. I'liila. Ao.ul. \a<. S<ri., 18<; (hivinjatti). 



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

 ments of OctoijUnn hivirgata^ tliis genus differs from rolyzonlumhyhay- 

 ing the first segments marginate and not concealing the ocelb". 



If liis figures are not trustworthy Oefoglena is equal to P<>Iifzonium. 



This genus contains the following species: 



Octoglena bivirgata. 



(hlixjlcna hirliffafn Wood. I'roc. I'liila. Ac.-id. Nat. S<i.. ISfi, \^yM { (S eonjia) ; Wood, 

 Trans. Aiiur. I'liil. .^oc. 22:). ISt^. 



H. — Platvdesmin.k. 



18(50. — riaiydeamii Saiissiire. Myr. Mex., 83. 



1872. — riatydesmia Humliert and Suiissme. Miss. sci. Mex., vi. 99. 

 1884. — Dolisteiiia Latzel. Myr. Ost.-Uugar. Alouarch., ii, .'5(52. 

 1887. — Platydtsviini Pocock. Ann. and Mag. Nat. Hist., 225. 



AnalffHia of the genera of I'latiidixmino'. 



a. Body narrow, filiform; mentumrectanjj;uiar; hypostouia not well developed; anal 

 scale absent; segments not tuberculate. 



1). Fifth segment normal, pores not carried on a pedicel Dolistents. 



hh. Lateral carin.e of fifth segment large, deeply sinnate, anterior lobe direc^ted 

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

 pedicf 1 ; other pores on a pedicel but opening on the posterior half of seg- 

 ments Androgxathus. — HI. 



Art. Body wide, depressed; nientnm hammer-shaped; hypostoma well developed; 

 anal scale present; segments tuberculate Platyuesmls. — IV. 



ANDROGNATHUS Copk. 

 1869. — Andrognathus Co^e. Pntc. Amer. Phil. Soc, 182 (corticarius). 



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

 ous short hairs. Head not rostrate (mouth parts not adapt-ed for suck- 

 ing), not concealed by first dorsal plate, densely pilose. xVnteniue 

 clavate, short. Ocelli absent. Gnathochilarium well developed, stipes 

 acuminate, destitute of molaand teeth; hypostoma rectangular; cardo 

 rather long and narrow, triangular; mentum rectangular; promentum 

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

 Dorsal jilates medianly sulcatc, not tuberculate. First dorsal plate 



