Western China and Eastern Thibet. 367 



are slight differences in the genitalia even in individuals from 

 the same locality, but in the majority of cases of a nature 

 more illusory than real. Some other investigator may be 

 more fortunate. 



Subfam. Gomphina. 

 Gomphus scissus, sp. n. 



? . Head shining black ; a spot on each side of the face at 

 the corners of the mouth, a rather broad transverse band at 

 the top of the front, and a small triangular spot at the back 

 of the middle of the occiput yellow; occiput strongly ciliated, 

 produced in its middle into an erect flattened tooth, which is 

 broad and triangular at its base, but afterwards strongly 

 acuminate, the apical portion narroio, the apex itself obtuse and 

 slightly bifid. Prothorax black, with a transverse nearly 

 interrupted median spot, followed by a short line. Thorax 

 black above, with grey pilosity, anteriorly with two trans- 

 verse yellow lines (forming the collar), separated by the 

 dorsal crest ; behind these is an oblique isolated short yellow 

 band on either side of the dorsal crest, and a small isolated 

 yellow spot below each band placed more outwardly ; two 

 small yellow dots in the sinus ; in the interalar area are three 

 yellow spots: sides yellow, a black line on the interalar 

 suture, connected anteriorly with a much angulated black 

 line which extends nearly across the pectus, which latter is 

 otherwise yellow. Legs short, wholly black. Abdomen 

 dilated at the base, but afterwards slender, black, marked 

 with yellow as follows : — above, a transverse spot on the 

 first segment, followed by a median longitudinal band on the 

 second ; a fine interrupted dorsal line on the third, continued 

 as a short basal line on the fourth to seventh, and a narrow 

 ring at the apex of the ninth. Sides marked as follows : — a 

 broad band on the first and second segments, continued as a 

 narrower band on the third (interrupted in the middle by the 

 false suture), a small basal and postmedian spot on the fourth 

 to eighth, and the lateral margins of the eighth and ninth. 

 Appendages about as long as the tenth segment, cylindrical, 

 acute, yellow, tipped with black, a rounded black protuberance 

 between them ciliated with black. Vulvar scale two thirds 

 the length of the ninth segment, black, divided almost to the 

 base into two long slender parallel spines, the apices of which 

 are slightly upcurved. 



Wings hyaline, strongly tinged with yellow to beyond the 

 triangles in the anterior, and nearly up to the nodus in the 



