80 burmeister's odonata. 



* Pr. b. sp. Drg." in B.'s hand, at Halle; no ])in-labelr! except a 

 hit of unmarked hlue paper on the pin of the male. A description 

 folhnvs : 



% (type). Vertex hlackisli, bifid, apices not acute. Froiis olive in front, yel- 

 lowish on the sides with the two vertical and the one horizontal carinse charac- 

 teristic for Orthetntm. Clypeus paler olive. Lips and rear of head luteons. Oc- 

 ciput olive above: rear of occiput with a distinct median vertical groove. 



Prothorax luteous, middle lobe reddish ; hind lobe not as wide as the middle 

 lobe, its hind marfjin entire. 



Thoracic dorsum luteous. the sides darker brown. A narrow black antehu- 

 meral stripe not reaching the base of the front wing; along its inner (median) 

 side runs an indistinct, pale olive stripe. Mesepimeron and metepimeron each 

 with a pale yellow stripe margined with black at their lower ends, ill-defined at 

 their upper ends. Tergal sclerites in interalar space pale yellow, axillary call] 

 brown. 



Femora blackish, reddish-brown on their superior surfaces near the base. 



Tibise blackish, the first luteous superiorly near base; the tliird with 10 ante- 

 rior (external), 8 posterior (internal) spines. 



Tarsi luteous superiorly, blackish inferiorly. 



Abdomen widest at base of 3, constricted and narrowest at base of 4, widening 

 to apex of 5, 9 and 10 of equal width ; luteous at base and inferiorly ; colors on 

 dorsum mostly faded, formerly apparently luteous with black marginal bands to 

 the segments. 



Superior appendages longer than fi, not as long as 9 + 10, black, almost straight 

 when viewed from above, with fairly acute apices; viewed from the side, thickest 

 at base and at three-fourths their length, of the usual form for Orthefrum, with a 

 row of 10-11 denticles on the inferior surface, apex acute, directed slightly 

 upwards. 



Inferior appendage about two-thirds as long, not reaching to the last (distal) 

 denticle of the superior appendages, triangular and with straight sides when 

 viewed from below, apex truncated and terminating in two upturned denticles. 



Genitalia of 2 agreeing with my description of those of truncatani Calv., but 

 not easily examined owing to the partial protrusion of the penis; the hook on 

 the outer side of the internal hamular branch very distinct. 



Wings hyaline, but with a slightly smoky tinge. Costa as far as the pteros- 

 tigma, the antenodals in the subcostal space and the cross-veins between the 

 median vein and the upper sector of the arculus yellow on all the wings; all 

 other veins black. Nodal sector distinctly waved. Supplementary sector next 

 below the subnodal separated from it by two rows of cells at a level corresponding 

 to that of the middle postuodals. Supplementary .sector next below the short 

 sector separated from it by one row of cells throughout. Upper end of arculus 

 at the second antenodal. One submedian cross-vein slightly nearer the base than 

 the first anteuodal is. Pterostigma yellow, surmounting one and parts of two 

 other cells (two cells and small parts of two othei's on left front wing). 



Front wings with 12 antenodals, the last continued to median vein, 10 post- 

 uodals; subnodal and nodal sectors parallel and separated by but a single row of 

 cells except at margin where there are two rows for a length of 2-3 cells ; internal 

 triangle of 3 cells; discoidal triangle with one cross-vein, followed by tiiree post- 

 triangular rows not increasing until on a level with the last antenodal ; first sector 



