268 PROCEEDINGS OF THE ACADEMY OF [May, 



Blattella inexpectata n. sp. 



Type: ? ; Demerara, British Guiana. 1901. (R. J. Crew.) 



In general appearance this form resembles B. parana (Walker) from 

 Para, but it is larger with a richer coloration and with the caudal 

 margin of the pronotum more arcuate. In some respects this species 

 resembles the vitrea-dilatata-pavida group but is more slender, bearing 

 a considerable superficial resemblance to Ischnoptera hlattoides. 



Size medium; form moderately depressed, elongate-elliptical; surface 

 glabrous. Head almost entirely covered by the pronotum, narrowest 

 portion of the interspace between the eyes slightly less than the depth 

 of one of the eyes; antennae well separated at the bases, in length ex- 

 tending caudad to the distal extremity of the caudal coxae. Pronotum 

 moderately transverse, ovate, narrow, cephalic margin subtruncate, 

 caudal margin moderately arcuate with an extremely slight median 

 angulation, lateral margins arcuate with the greatest width very slightly 

 caudad of the middle; lateral sections moderately depressed. Tegmina 

 slightly exceeding the apex of the abdomen, the greatest width con- 

 tained slightly more than three times in the length; costal margin 

 arcuate, the arcuation of the proximal third much greater than that of 

 the remainder of the margin; sutural margin nearly straight, very 

 obhquely truncate in the apical fourth where it turns to meet the nar- 

 rowly rounded apex ; basal field narrow and covering slightly more than 

 a third of the length of the tegmen; anal field obovate in shape and 

 about equalling the basal field in length ; costal veins about f om'teen in 

 number, median vein with four rami, the distal of which has four 

 branches, some of which has the branching carried two stages farther; 

 anal area with five veins. Wings with the costal veins numbering 

 about nine, the majority of the veins being distinctly incrassate distad; 

 anterior ulnar vein bearing three complete rami. Supra-anal plate 

 trigonal with a rather large median emargination; cerci about equal 

 to the subgenital plate in length, fusiform; subgenital plate moderately 

 inflated, somewhat tectate, apical margin shallowly emarginate, well 

 marked cereal sinuations present. Cephalic femora armed on the 

 ventro-cephalic margin with four large median and one large distal 

 spine, the intervening area filled with fine comb-like spines. Median 

 and caudal femora with the ventral margins spined. 



General color ochraceous, becoming ochraceous-rufous on the disk 

 of the pronotum and the section of the tegmina which when in repose 

 cover the body. Eyes bistre; lateral sections of the pronotum and 

 costal section of the tegmina translucent ochre yellow, the section 

 of the left tegmen which in repose is covered by the right is very pale, 



