No. 1571. DRAGONFLIES OF BURMA AND SUM— WILLIAMSON. 



277 



is distinguished by De Selys from nipalensis De Selys, occurring in 

 Nepal, as follows: By yellow venation instead of black; by a large 

 yellow ring on al^dominal segment 10, wanting in nipalensis, and 

 by other characters. TTiecagaster is represented by two species from 

 North India (North India and Himalaya). These species, originally 

 placed m this genus by De Selys, were later definitely referred l)y 

 him to Cordulegaster (Causeries Od. No. 7). The two species, hrevi- 

 stigrna De Selys and parvistigma De Selys, have the abdomen black 

 wdth dorsal spots in a half ring. T. hremstigm-a has 14 or 15 ante- 

 nodals in front wing, while parvistigma has 21. Some other differ- 

 ences mentioned by De Selys are: T. brevistigma has the upper lip 

 bordered with black, and abdominal segment 10 black with a lateral 

 longitudinal yellow spot; parvistigma has the upper lip not bordered 

 with black, and 10 without yellow markings. Representatives of 

 the subfamily Cordulegasterina? will certainly eventually be found in 

 Burma and probably also in Siam. (See fig. 4.) 



Subfamily OIILiORO&OM:PH:iJSr.fE. 



Genus CHLOROGOMPH US De Selys. 



This genus is represented by two species confined to Sumatra 

 and Java. 



Fig. 5.— Wings of male OROGOMPHrs atkinsoni. De Selys' collection. 



Genus OROGOMPHUS De Selys. 



Three species are known, found in Luzon, Bengal, Tonkin, and 

 Burma. The three species are distinguished by De Selys as follows: 

 0. splendidus De Selys, Luzon and Tonkin, and speciosus De Selys, 



