NO. 1571. DRAGONFLIES OF BURMA AND SIAM—WILLIAMSOX. 313 



Antenodals, front wing 14-16; hind wing 9-11 ; postnodals, 

 front wing 9-10; hind wing 10. Head black, yellow as follows: Two 

 spots on upper lip, rhinarium, a small spot at the iij^per end of 

 nasus, frons above with a s})ot on each side; lower lip ])ale. A 

 narrow pale antehuineral stripe, widened into a spot above. Sides 

 of thorax yellow, the two lateral sutures with black stripes, wider 

 on the first. Legs black. Abdomen with basal rings on 3-7 narrowly 

 interrupted above, about one-third to one-fourth the length of each 

 segment, largest on 7; median dorsal spot on 3 and 4 and a trace 

 on 5; 8-10 black. Female vulvar lamina one-fourth length of 9, 

 rounded triangular, apex notched; female occipital plate with hind 

 margin almost straight, slightly lower at the middle; female abdomi- 

 nal appendages a little longer than 10, yellow, a short black tubercle 

 between them. The venation of the female figured in this paper 

 is peculiar for the genus, so far as known to me, by the position of the 

 arculus in the front wing, slightly beyond the second antenodal, and 

 by having the second postanal cell in the hind wing divided. 



17. ONYCHOGOMPHUS MACLACHLANI De Selys. 



^'Patrie: Le Nord de la Birmanie. Une female unique (collect. 

 McLachlan)." 



Head black, frons above with an anterior yellow stripe nar- 

 rowed at the middle. Sides of thorax black, with a yellow stripe on 

 the mesepimeron and metepimeron. Legs brownish black. Abdom- 

 inal segments 3-7 with basal yellow rings occupying about one-fifth 

 of each segment: S with a small basal spot on each side replacing 

 the ring. 



18. ONYCHOGOMPHUS? SPECIES. 



A single male in fragments from Earnshaw in my collection. 



Hind wing 33 mm. Antenodals, front wing 13, hind wing 10; 

 postnodals, front wing 10, hind wing 9. 



Lower lip pale yellow ; upper lip yellow, bordered basally and ante- 

 riorly and traversed medianly ^vith black; rhinarium yellow, below 

 on either side black; nasiis black, a narrow margin below at the 

 middle and a large spot at either end yellow; frons yellow, in front 

 the lower half and above a median basal triangular spot, not dividing 

 the yellow, black; occiput nearly straight, yellow, black against 

 the eyes; rear of head black. 



Prothorax black, margined with yellow. Thorax above black, 

 middorsal carina below narrowly yellow; yellow stripes joined below 

 with the uninterrupted mesothoracic half collar to form a 7 on each 

 side of the carina; the antehumeral yellow stripes represented by a 

 spot above and a smaller one below; first lateral thoracic suture with 

 a black stripe interrupted to form 3 short stripes; second lateral suture 



