Keuroptera fruin Western China. 431 



spot at tlie base of the posterior not reticulated with yellow ; 

 ami (8) the black ventral surfoce, ornamented with very 

 tlistinct isolated yellow marginal spots. Tliese combined 

 ditl'erenccs are arrived at alter a comparison with about rttty 

 examples of L. quadrimaciUata from various parts of Europe, 

 Northern Asia, and North America. 



In size L. hasilinea equals tiie largest L. quadrimaculata. 



In the basal streaks L.basiUnea has aflinity with L. an(je/ina, 

 Selys, from Japan, but in the latter there is a large triangular 

 blackish spot under the ptcrostigma in all the v/ings, the basal 

 triangular spot of the hind wings is reticulated with yellow, 

 and the abdomen has no clearly defined yellow spots ; but 

 there is sometimes an approach, towards them to be seen in 

 L. quadriinaculata. 



I have compared the appendages and genitalia of the 

 second segment and the vulvar scale, without finding ajjpre- 

 ciable ditierences between L. quadrimaculata and L. hasi- 

 linea, and I am not sure that any such exist between L. ange- 

 lina and L. quadrimaculata, though the genitalia of the second 

 segment look rather different. 



Having regard to the fact that the only two individuals in 

 the collection are precisely similar in their essential cha- 

 racters, I can only arrive at the conclusion that they represent 

 a condition equally worthy of specific rank as is L. angelina 

 of Japan. 



Orthetrum japonicum., Uhler, var. n. internum. 



Differs from the typical O.japonicum as follows : — In the 

 labium the middle lobe is icholly blackish and the side-lobes 

 are broadly margined (sometimes nearly wholly) with the 

 same colour. On the thorax the black band separating the 

 two large yellow spaces on the sides is broader, without (at 

 any rate in adult examples) any trace of containing a yellow 

 line. 



In the wings the pterostigma appears to be slightly 

 narrower and more or less deep black in adult individuals ; 

 the triangle of tJie posterior wings apparently invariably tra- 

 versed by a nervule (without any nervule in the type form). 



Nine males and one female, all very adult. 



These may represent a species distinct from O.japonicum^ 

 and the fact that the triangle of the posterior wdngs is appa- 

 rently always traversed by a nervule (in one example the 

 triangle of the anterior is traversed by two nervules) may be 

 sufficient to separate it ; but having in view the instability of 

 this character in individuals of other species from one locality, 



