MORGAN HEBARD 171 



We have of recent years ])een giving much attention to the 

 concealed genitalia of the Blattidae and find that in these organs 

 chitinous parts are developed, which frequently afford char- 

 acters of full specific diagnostic value. These chitinous parts 

 very often are as constant as the specialized portions of the 

 subgenital plate, occasionally they are seen to develop slight 

 individual differences in contour. The present case, however, 

 is the first we have encountered, where a distinct difference is 

 found which we feel obliged to look upon as an individual 

 variation. 



NYCTIBORINAE 

 Nyctibora tetrasticta new species (Plate [VI, figures 13, 14 and 1.5.) 



This species agrees with N. truncata Saussure and Zehntner-'^ 

 in being flightless, the tegmina decidedly reduced, the wings 

 represented by vestigial pads. It differs from that species in 

 being somewhat larger, the male sex showing conspicuous 

 a])dominal markings. 



Type. — cf ; Venvidio, Sinaloa, Mexico. July G to 12, 1918. 

 (J. A. Kusche.) [Hebard Collection, Type no. 760.] 



Size small for this genus of large species, slightly larger tlian truncntd and 

 N. azteca Saussure and Zehntner; surface glabrous, but, thickly supjilied with 

 minute, microscooic, procumbent hairs springing from microscopic impressed 

 punctulae. Head elongate and flattened; interocular space narrow, less than 

 one-quarter width between antennal sockets, interocular area flattened, 

 ocellar spots moderately large, not as large or with ocellar areas weakly 

 defined as in azteca. Maxillary palpi with fifth joint enlarged, slightly longer 

 than third, fourth half as long as fifth. Pronotum evenly convex, jioint of 

 greatest width at latero-caudal angles, cephalic margin nearly semicircular 

 to the rounded rectangulate latero-caudal angles, between these the caudal 

 margin is nearly transverse, showing very bread, rounded obtuse-angulation. 

 Tegmina overlapping, somewhat longer than broad, venation subobsoletc, 

 the humeral trunk and veins at caudal margin only appreciable imless the 

 tegmina are held up to the light, anal sulcus distinct only at sutural margin, 

 to which margin it is perpendicular; costal margin rounding broadly to sutural 

 margin, so that the median segment only is ccmjjletely covered. Wings 

 vestigial, repres(!nted by lateral pads. Abdominal tergites witli caudal 

 margins transverse, fourth tergite with latero-caudal angles weakly acute- 

 angulate produced, fifth and sixth with these angles increasingly jjroduced, 



'" From T£Tpa-aTtKTT]=four-spotted. 



-" After careful consi<leration of the descri|)t ion of Xyclih(»-a {[Icmitu/ctihnra) 

 truncata, we feel that Kirby is unwarranted in elevating IluniinyrHbora to 

 generic rank and that the name should be j)la('ed in synonymy under Nycti- 

 bora. The (!haracter of rechiced organs of flight, alone given as a basis for 

 that name, is insufficient. 



TRANS. AM. ENT. SOC, XLVIU. 



