22 NORTH AMERICAN BLATTIDAE 



D. Subgenital plate valvular, with bases of valves forming an acute angula[- 

 tion. Cerci much reduced, articulations apparent, apex acute. (Size very 

 small. Ocelli absent. Ventral femoral margins unarmed.) . .Compsodes *° 

 DD. Subgenital plate simple. Cerci very greatly reduced, articulations 

 obsolete, apex blunt. (Pulvilli absent.) 

 E. Ocellar spots absent. Size minute. Ventro-cephalic margin of cepha- 

 lic femora armed with a single, delicate, distal spine, other ventral mar- 

 gins unarmed, except cephalic margin of caudal femora, which is supplied 

 with several stout spines. Cerci rounded lobes. Large arolia present. 



(General coloration amber yellow.) Attaphila fungicola Wheeler 



EE. Ocellar spots present, usually very weakly defined. Size large to 

 medium small. Ventral femoral margins unarmed, except for a rather 

 closely set row of short, chaetiform spines in distal half of cephalic margin 

 of cephalic femora. Cerci greatly reduced, blunt conical. Arolia absent. 



Arenivaga ^i 



CC. Median and caudal femora lacking a disto-dorsal genicular spine. (Arolia 



absent.) 



D. Subgenital plate simple. Size medium small, form suborbicular. Insect 



exceedingly hairy. Ocellar spots very weakly defined. Cephalic femora 



with ventro-cephalic margin bearing a few stout, rather closely placed, 



conical spines, succeeded distad by a series of very widely spaced, similar 



spines; otherwise the ventral femoral margins are unarmed, but extremely 



hairy. Tarsi greatly reduced; pulvilli absent; tarsal claws reduced and 



scarcely functional Eremoblatta subdiaphana (Scudder) 



DD. Subgenital plate absent, distal portion of abdomen covered by the 

 produced sixth dorsal and ventral abdominal segments. Size medium, form 

 elongate. Insect smooth. Ocelli absent. (Coloration shining blackish 

 brown.) (Pronotum thickened and somewhat hooded cephalad.) Cephalic 

 femora with ventro-cephalic margin armed distad with two or three stout 

 spines, ventro-caudal margins of all femora (normally) armed with two 

 similar distal spines, other ventral femoral margins unarmed. Four proxi- 

 mal tarsal joints heavy, each bearing a pul villus; tarsal claws heavy. 



Cryptocercus punctulatus Scudder 



A cknowledgements 



The material treated in the present study totals 5354 speci- 

 mens, of which 3788 are in the Philadelphia collections. 



''"The female sex is unknown of the single species found in North America, north of 

 the Mexican boundary. The characters here given are of generic significance and are 

 taken from females before us of Compsodes delicatulus (Saussure and Zehntner). 



" A key to the females of the North American species of the Polyphaginae is given on 

 page 217. The four species of Arenivaga, found north of the Mexican boundary, are 

 there tabulated. 



