EMBIA MAJOE FEOM THE HIMALAYAS. 179 



4. A Table of Comparison of the Principal Differences between the Sexes. 

 Male. Female. 



Winged. Winy less. 



Body-hairs brown-black or black, absent for the Body-hairs light brown, longer than in male, 

 most part from the dorsal surface of the thorax present to some extent on the dorsal surface of 



and abdomen. the thorax and abdomen. 



Maximum length 18 mm. Blaximum length 20 - 75 mm. 



Head, thorax, and abdomen related iu length as Head, thorax, and abdomen related in length as 

 3:5:8. 3:7:10. 



Eyes reniform. Eyes smaller, less markedly reniform. 



Antennae 6-7"5 mm. in length, longer than the Antennas 5-6 mm. in length, shorter than the 

 thorax. Joints 20-29 ; the combined length thorax. Joints 23-29 ; the combined length 



of 4th-6th joints exceeds that of the first two of 4th-6th joints less than that of the first two 



joints. joints. All the joints shorter and more annular 



than iu male. 



Mandibles slender, biting-edge but little de- Mandibles massive, biting-edge armed with four 

 veloped. prominent teeth. 



Apical teeth of lacinia of 1st maxilla small. Apica) teeth of 1st maxilla larger and more 



prominent. 



Thoracic segments short ; the terga of the meso- Thoracic segments elongate ; the terga of the 

 and metithorax modified in correlation with meso- and metathorax simple and unmodified, 



the presence of wings. 



Abdomen consists of ten tergal and nine evident Abdomen consists of ten tergal and ten sternal 

 sternal plates. plates. 



The 10th tergum divided into two asymmetrical The 10th terguni undivided; both it and the 

 shields. The 9th tergum also asymmetrical. 9th tergum symmetrical. 



The 9th sternum enlarged and markedly asym- The 9th sternum not enlarged, symmetrical, 

 metrical. It is probably a composite structure The 10th sternum in the form of two sy in- 



formed by the right plate of the 10th sternum metrical shields, 



becoming fused with it. The left plate of the 

 10th sternum is probably represented by the 

 " ventral process.'' 



The basal joint of the left cercus much enlarged. The basal joint of the left cercus not enlarged, 



similar to that of the right side. 



The genital aperture terminal in position, the The genital aperture ventral in position, the 

 9th sternum forming the subgeuital plate. 8th sternum forming the subgenital plate. 



The external genitalia formed by the curved External genitalia absent. 



process of the left shield of the 10th tergum 



and the " ventral process " attached to the 

 9th sternum. 



