NO. 1571. DRAGONFLIES OF BURMA AND SIAM— WILLIAMSON. 301 



A male from Burma was sent to M. Martin, who writes as follows: 

 ''It is a species very near to vermiculatus but slenderer, the stripes 

 of the thorax different, the inferior appendage slenderer and more 

 divaricate." Specimens from Anam and Tonkin are slightly larger, 

 abdomen 30-32 mm., and the antenodals and postnodals are more 

 numerous; as described the nasus is not spotted and the pale dorsal 

 stripe on the frons is divided; the black stripe on the first lateral 

 suture is forked above, not reduced as in the specimens from Burma; 

 and the color pattern of the abdomen is slightly different, with 9 

 bearing a small posterior spine, wliicli is not represented in my 

 material. 



II. BURMAGOMPHUS VERMICULATUS Martin. 



Abdomen, male 28 mm. ; hind wing, male 23 mm. Antenodals, 

 fi'ont wing 10, hind wing 8; postnodals, front wing 8-9, hind wing 

 8-10. Second thickened antenodal normally the fourth; oblique 

 vein the second or third beyond the subnodus; stigma covering 3-4 

 cells, followed in the front wing by about the same number; triangle 

 in front wing followed by 2 rows of cells, in hind wing by 3 rows, 

 then 2 increasing; anal triangle 3-celled. 



Head 6 mm. wide, distance between eyes above at closest point 1 

 nun.; black throughout exce])t as follows: Lower lip white or pale 

 plumbeous, paler at the margins; a large transverse rectangular green 

 spot on either side of the upper lip at its base; the base of the man- 

 dibles green; a short, narrow, transverse, median, inferior streak, and 

 a large rounded spot on either side of the nasus; frons low, yellowish 

 green above in front, black at the base, the black extending anteriorly 

 at the middle in a broad low triangle, but not dividing the pale area, 

 and widening on either side, giving the pale area a rounded posterior 

 border on either side of the median line; eyes in dried specimens 

 chestnut brown, probably in life blue, shading below into pale. 



Prothorax black, the dorsal anterior border narrowly yellow; a 

 greenish-yellow triangular spot on either side of the posterior border, 

 and a smaller spot below this on the inferior margin; these spots 

 represented below by a short pale streak at the bases of the first 

 legs. Thorax black, marked with greenish yellow as follows: A 

 mesothoracic half collar, interrupted l)y the merest line, wide on 

 either side of the median line and tapering to an acute apex at either 

 extremity; widely divergent dorsal stripes, the lower portion of 

 which really consists of a portion of the antehumeral stripes (see 

 diagram of thoracic pattern, fig. 29), continued below as a pale 

 stripe extending on to the bases of the middle legs; a dorsal ante- 

 humeral spot; a wide stripe on the mesepimeron, joined above for 

 about one-third its length with a wider stripe on the metepisternum, 

 the later stripe Extending below on to the metinfrEepisternum and 

 with its upper posterior corner more or less isolated by a narrow black 



