372 Mr. R. M'Lachlan on Odonata from 



These offer no peculiarities other than in abdominal sexual 

 characters. In less highly mature examples the terminal 

 segments of the abdomen are not pruinose above and the 

 wings are simply hyaline, with no olivaceous tinge. Possibly 

 the pterostigma is slightly shorter than in the male. The 

 point of insertion of the nodal sector is slightly variable in 

 different individuals, and there is sometimes only one nervule 

 in the quadrilateral of the hind wings (in one individual there 

 is only one such nervule in the right anterior and left poste- 

 rior wing and two in the other wings). 



Length of abdomen '63-35 millim. ; length of posterior 

 wing '31-33 millim. 



Subf;.m. Ageionina. 

 MesOPODAGEION, g. n. (le'gion Podagrion) . 



Nodus placed at one third the distance from base to ptero- 

 stigma. Pterostigma short-oblong, dilated, surmounting 

 three cellules. Quadrilateral with its upper edge two thirds 

 the length of the lower, so that the outer edge is strongly 

 oblique. Wings ceasing to be petiolated before the basal 

 postcostal nervule, which is near the level of the second ante- 

 nodal. Arculus coincident with the second antenodal. Post- 

 costal area with one row of cellules. Subnodal sector com- 

 mencing from the prolongation of the nodal vein, the median 

 markedly before. Two supplementary sectors between the 

 ultranodal and nodal sectors and between the nodal and sub- 

 nodal, one between the median and short sectors. 



Labium deeply divided, the lobes distant, subacute at apex. 

 Second joint of antennas somewhat longer than first. Abdo- 

 men moderately stout, cylindrical. Superior appendages of 

 male longer than tenth segment, forcipate. Legs moderate, 

 stout, spines long, claws minutely toothed below apex. 



Having the facies of Argiolestes, but with a single row of 

 postcostal cellules, and distinct from all Old- World forms of 

 the legion in consequence of the wings ceasing to be petiolated 

 before the basal postcostal nervule. 



Mesopodagrion tibetanum, sp. n. 



£ . Black ; head clothed with rather long greyish hairs ; 

 labrum, a spot on each side of it, and another spot on each 

 side below the base of the antennae greenish yellow ; two 

 minute oblique lines (one on each side of the ocelli) and a 

 short line on the middle of the occiput yellowish ; a large 



