SOME SIAMESE TABANIDAE. 44] 



at its lower extremity, but from level of upper end of main portion of callus to vertex 

 increasing considerably in width (see fig. 3a), sparsely clothed below and on lateral 

 margins with appressed, glistening ochreous hairs, and above with short, erect 

 blackish hair, vertex with a depressed, shining black median area shaped something 

 like a truncate triangle, but with no trace of an ©cellar tubercle ; frontal callus blackish- 

 brown, narrow and elongate, its upper extremity produced into a stout, linear ex- 

 tension, slightly longer than main portion of callus, and reaching to a point a little 

 above midway between level of lower inner angles of eyes and hind margin of vertex ; 

 proximal segment of palpi clothed below with buff-yellow hair and on upper border 

 of outer side with black hair, distal segment in $ acuminate and rather narrow, 

 mouse-grey on outer side except at extreme base, inner side and extreme base of 

 outer cinnamon-drab, outer surface clothed with minute, appressed black hairs, 

 a few glistening buff-yellow hairs at base below ; first and second segments of antennae 

 light fuscous or olive-brown, clothed with black hair, first segment broadening from 

 base to tip, with its upper distal extremity partially enveloping second segment, 

 upper distal angle of latter strongly produced, third segment russet, expanded portion 

 slightly longer than annulate portion, fairly deep at base, with angle on upper border 

 strongly produced upwards and forwards (see fig. 3). Thorax : Pleurae dark olive- 

 buff poUinose, scutellum somewhat paler pollinose, dorsum of scutum (in partially 

 rubbed specimen) with more or less distinct traces of four ill-defined, dark brown, 

 longitudinal stripes ; dorsum of scutum clothed with fine, erect, glistening honey- 

 yellow hair, pleurae and dorsal surface of scutellum clothed with similar hair of a 

 paler (yellowish) tint. Abdomen : Tergite of first (visible) segment Isabella-coloured, 

 clothed with fine, short, appressed, glistening honey-yellow hair ; remaining tergites 

 clothed for most part with short, appressed, black hair, with which on central portion 

 of second tergite honey-yellow hair like that on first tergite is freely mingled ; hair 

 clothing whitish pollinose hind margins of second to fourth tergites mainly silvery- 

 white, but some glistening honey-yellow or ochreous hairs also present on or just 

 in front of hind margins of second and third tergites, except at sides ; venter at 

 extreme base greyish-olive or neutral grey pollinose ; sternite of (nominal) second 

 segment, on each side in front of hind border, clothed for most part with minute, 

 appressed, glistening yellowish hairs ; seventh segment clothed above and below 

 with longer black hair ; sternites of (nominal) second and following segments, except 

 as already stated, clothed with minute, appressed black hair. Wings : Stigma 

 ochraceous-tawny, elongate and tapering ; costa, and main stem of third longitudinal 

 vein except at base, mummy-brown, veins otherwise for most part cinnamon-brown 

 or amber-brown ; in addition to usual hyaline streak in base of marginal cell, before 

 stigma, and usual hyaUne spot on fourth longitudinal vein, immediately before origin 

 of anterior basal transverse vein, all cells, except costal, basal and anal cells, show — 

 at least in typical specimen — a more or less distinct hyaline mark, varying in size 

 and shape in the different cells. Squamae pale Isabella-coloured (margins lighter or 

 darker according to incidence of light), fringed with pale yellowish hair. Haltercs 

 cream-buff, base of knobs (in dried condition) cinnamon-brown. Legs : Coxae dark 

 olive-buff pollinose, clothed with yellowish hair like that on pleurae ; front and hind 

 trochanters mouse-grey, hind pair clothed partly with yellowish, partly with dark 

 brown hair, trochanters of middle legs cinnamon, with darker markings ; middle 

 femora cinnamon at base, extreme tips of all femora cinnamon-buff ; tibiae, tarsi, 

 and femora for most part clothed with black hair, posterior surface of middle femora, 

 except at tips, clothed with long and fine yellowish hair, glistening ochreous hairs 

 also present at base of middle femora in front, and at base of hind femora above and 

 below, front femora fringed posteriorly with fairly long black hair ; front tibiae not 

 thickened, second and following segments of front tarsi, especially fourth segment, 

 considerably expanded in 2 ; claws long, entirely black ; pulvilli ochraceous-buff. 



Doi Chom Chang, near Chiengmai, alt. 5,500 ft., 15.iv.l921. Writing of the holo- 

 t^'pe of this species, Dr. Barnes says : " This specimen was caught while attacking 



