160 



[April, 



A NEW DRAGON-FLY OF THE GENUS AXAX FROM MADAGASCAR. 



BY ROBERT McLACHLAN, F.R.S., &c. 



Anax tumorifee, n. sp. 



Length of abdomen {cum appendic), (J, 63 mm., 9 , 60 ram. Length of pos- 

 terior-wing, (J $ , 53 mm. Expanse, S ? » 109 mm. 



$. Wings hyaline (not tinted). Neuration black (a few transverse nervules, 

 near the base, brownish) ; costal nervure yellow externally. Membranule blackish, 

 whitish at base. Pterostigma brown, rather short (5 mm.), very narrow. 18 ante- 

 cubital and 10 post-cubital nervules in the antorior-wings. Face and mouth-parts 

 yellowish (probably green in life) ; labrum regularly excised, the excision bordered 

 with very pale brown. Top of front slightly produced, semi-circular anteriorly, where 

 it is slightly margined by a greyish line; a large, nearly circular, black spot, not 

 produced in the middle, but the outer edge with four or five not very distinct denti- 

 culations : vesicle black behind, yellow in front (with a crest of black hairs) ; for a 

 short distance on cither side is a narrow black line margining the eyes. Antennse 

 black. Occiput yellow, flat, triangular, slightly rugulose. Back of head yellow, 

 margined with black above in the middle. 



Thorax yellowish (probably green in living insects), with fine cinereous pubes- 

 cence. 



Legs shining black ; anterior femora yellowish beneath ; length of posterior 

 femora, 10 mm. 



Abdomen slender (not depressed), cylindrical, considerably swollen, and after- 

 wards constricted, at base. Colour dark brown (altered), with indications of a black 

 doi'sal line, twice expanding on segments 4 — 7. Lateral impressions extending from 

 segments 3 — 9 (but only faintly indicated on 3 posteriorly). Segments 9 — 10 slightly 

 depressed, each slightly broader than long, and sub-equal. Segment 10 with a blunt 

 central longitudinal carina, on either side of which are two fovese, one posteriorly 

 the other anteriorly, the latter being larger and deeper than the former. 



Superior appendages long (8| mm.), nearly equalling segments 8 — 10 united, 

 piccous, somewhat castaneous intei-nally ; they are slender, and their outer edges 

 nearly straight up to the incurved apices ; a strong 

 raised keel above from the base to near the apex : the 

 inner edge is at first straight, but somewhat before the 

 middle it is enlarged into a very strong obtuse dilata- 

 tion (the edge of this dilatation is granulose if viewed 

 laterally), after which it is broadly excised, and again 

 slightly dilated to the apex, which is very obtuse, in- 

 curved, viewed above it has a rather broad explanate mar- 

 gin beyond the elevated subapical portion : the upper 

 sui'face is deeply concave between the central keel and 

 the raised outer edge up to the elevated sub-apical 

 portion ; the lower surface shallowly concave, with the 

 outer and inner edges much raised j the inner edge be- 

 yond the dilatation is double with a concavity between, 

 somewhat resembling the lateral impressions on the abdomen. Inferior appendage 





