1902.] DRAGONFLIES OF THE " SKE.AT EXPEDITION." 73 



is free, in three females crossed ; in males it is normally free.) 

 Two rows of post-triangular cells. Nodal sector strongly waved at 

 its middle. Arculus at the level of the second antenodal. Two 

 cross nervules in the submedian space. 



Hind wings. 10-11 antenodals, 9-9 postnodals. Discoidal 

 triangle traversed. (According to de Selys the discoidal triangle 

 of the hind wing in the female is normally traversed ; of 13 males 

 7 had it traversed and 6 free.) The triangle is followed by two 

 rows of cells. The British Museum specimen (male) has but one 

 row of post-trigonal cells in the hind wings. Pterostigma in the 

 females is about 3*75 mm. long, in the male about 2*25 mm. 

 Sectors of triangles of hind wings widely separated at their origins. 



Rhinarium and nasus livid yellow. Frons and vertex metallic 

 blue-green. Thorax metallic blue -green. Abdomen slightly 

 thickened at its base, metallic black with jS.ne transverse yellow 

 lines at the bases of segments 2 and 3 and on the transverse 

 carinas of those segments. A yellow spot on either side of the 

 second segment. 



Legs black. In the males on each of the second pair of femurs 

 are a number of short teeth directed towards the knee. On the 

 third pair are 25 short teeth ; of these the first eight or nine are 

 directed towards the knee, then follow one or two not inclined, 

 then eleven or twelve directed towards the trochanter, last one 

 or two not inclined. In the females all the teeth on the hinder 

 femurs are directed towards the knee. 



Zygonidia malayana, sp. u. 



Length of abdomen 34:"5 mm. Length of hind wing 42 mm. 

 Length of pterostigma 3*75 mm. Breadth of hind wing 13 mm. 



Wings hyaline, reticulation black, pterostigma black, mem- 

 branule brownish grey. 



Fw^e wings. 16 antenodals, the last on the right side is dis- 

 continuous, that on the left continuous. 9 postnodals. Internal 

 triangle divided into three cells, discoidal triangle crossed by a 

 single nervule and followed by three rows of cells. Nodal sector 

 waved at its middle. Two cross nervules in lower basal cells. 

 Arculus between the level of the first and second antenodal. 



Hind wings. 10-11 antenodals, 10-11 postnodals. Discoidal 

 triangle traversed, followed by two rows of cells. Sectors of 

 triangle scarcely separate at their origin. Lower basal cell with 

 a single cross nervule. 



Head. Labrum black, bases of the mandibles bright yellow. 

 Rhinarium dull yellowish brown, nasus black along its ventral 

 margin, for the rest yellow. Gense yellow. Frons and tubercle 

 metallic violet, but frons yellow at the sides. Tubercle truncate 

 anteriorly, occipital triangle black. 



Prothorax brown, posterior lobe with a rounded backwardly 

 directed projection at the middle of its posterior margin. 



Thorax metallic green, marked with dull yellowish brown as 

 follows : — a fine line along the mid-dorsal carina ; a lateral band 



