24 NORTH AMERICAN BLATTIDAE 



fades, convinces us that, though representing one of the nearly 

 intermediate genera, this insect belongs properly in the Pseuclo- 

 mopinae. 



The Group Blattellites 



The species of this group are all delicate, this particularly evi- 

 denced in the tegminal structure. The tegmina have their dis- 

 coidal sectors longitudinal, weakly oblique or decidedly oblique to 

 the discoidal vein. The wings have the ulnar vein with rami all 

 complete to the distal margin. 



In order to place correctly the North American species of this, 

 the first and largest, group of the Pseudomopinae, we have been 

 obliged to examine carefully our considerable series from the sub- 

 tropical and tropical regions, south of the southern limits of the 

 United States. The far greater portion of this material is as yet 

 unrecorded, and, during the preparation of the present paper, 

 only such work has been done as was necessary to determine the 

 correct relationship of the forms related to, or confused with, those 

 found over that portion of the continent at present under consid- 

 eration. Several features of decided importance should, however, 

 be stated here concerning this material. 



There is absolute proof that unusually great numbers of species 

 yet undescribed of this group exist in tropical America; all have 

 excellent structural characters, but in the males of different species 

 the genitalic features and secondary sexual modifications of the 

 abdomen are particularly complex and valuable. The group is 

 difficult and almost the despair of the systematist, this latter fact 

 due almost wholly to a universal practice in the past of describ- 

 ing species briefly, usually with no reference to any of the char- 

 acters of major importance, this naturally resulting in frequent 

 subsequent misidentifications. Until the types of all the old 

 species are fully described, or topotypic material secured (which 

 can often solve such problems), the tropical American species 

 should, whenever treated, be given full and careful consideration 

 with reference to genitalic and other features of importance, mere 

 records in some cases only adding to the difficulties now existing. 



