SOME SIAMESE TABANIDAE. 447 



fringed with very short and inconspicuous yellowish liair ; front in $ of moderate 

 width, which diminishes very slightly from above downwards, length of front equal 

 to about six times its breadth between lower inner angles of eyes, vertex exhibiting a 

 median, blackish, elongate mark, but ocellar tubercle wanting ; a single frontal callus 

 (see fig. 5), which is blackish-brown, bottle-shaped in outline and sharply defined, 

 relatively fairly broad yet clearly though narrowly separated from each eye, its 

 lower margin straight and on a level with lower inner angles of eyes, its upper extremity 

 produced into a stout, tapering extension reaching to a point a little above half the 

 length of the front : eyes bare (no trace of a band or bands visible in dried condition, 

 in case of type) ; palpi pale pinkish-buff, proximal segment clothed with whitish hair 

 (its outer surface — except tip, perhaps tinged with neutral grey), chstal segment 

 considerably swollen at base, then tapering to a slender point, its outer surface clothed 

 with minute, appressed whitish or yellowish- white hairs, mixed with minute, appressed 

 black hairs ; antennae cinnamon-rufous, annulate portion of third segment (at least 

 in case of type) blackish-brown, distal half of expanded portion infuscated on outer 

 side, first segment light greyish pollinose above, clothed with minute black hairs on 

 upper surface and with yellowish hairs below, its upper distal angle considerably 

 produced and embracing second segment, latter small, its distal extremity ringed with 

 minute black hairs, its upper distal angle small and sharp, not projecting beyond that 

 of first segment, expanded portion of third segment in $ narrow and elongate (see 

 fig. 5), with a sharp, prominent angle on upper margin a little beyond end of proximal 

 third, length of annulate portion equal to about three-fifths of that of expanded 

 portion. Thorax : Dorsum of scutum longitudinally striped with light olive-grey, in 

 manner frequently seen in genus Tabanits — a short mecUan stripe on front border, 

 not extending quite half-way to transverse suture, and on each side of this, between 

 it and lateral margin, a somewhat broader, uninterrupted stripe, reaching to posterior 

 margin of scutum ; lateral borders of scutum pale olive-grey, dorsal surface of scutel- 

 lum unreheved by lighter markings, its lateral margins light drab ; dorsum, including 

 scutellum, clothed with a mixture of minute, appressed cream-buff or \'ellowish hairs, 

 and short, fine, erect blackish hairs ; swelling occup\ing depression at each end of 

 transverse suture mouse-grey, and clothed mainly with black or blackish hair ; a 

 strip on each side, commencing above base of wing and including lower border of 

 post-alar callus, clothed with whitish or silvery-white hair ; pleurae and pectus pale 

 smoke-grey, clothed with whitish hair . A bdomen : Median stripe on dorsum commen- 

 cing on first (visible) segment and terminating abruptly on hind margin of sixth, 

 diminishing somewhat in width posteriorly and on second to fourth tergites, inclusive, 

 clearly constituted in each case by a narrow truncate triangle, with its base resting 

 on hind margin ; ground colour of stripe smoke-grey pollinose ; stripe thus formed is 

 clothed with minute, appressed, ghstening Naples yellow hairs, the combined effect 

 being light buff ; second to fifth tergites, inclusive, each with alight buff, longitudinally 

 ovoid spot on each side, midway between median stripe and lateral margin, these 

 spots or blotches similar in composition to the median stripe itself, but those on fifth 

 segment very small and faint ; sixth tergite on hind margin on each side with a small 

 patch of appressed Naples j'ellow hairs, representing and in continuation of the spot 

 on the preceding segment, more distinct vestiges of actual spots being visible on sixth 

 segment when abdomen is viewed at a low angle from behind ; ground colour of sides 

 of second to sixth tergites, inclusive, cinnamon-rufous ; lateral extremities and hind 

 margin of seventh tergite cream-buff, clothed parti}' with ghstening Naples yellow 

 hair, and partly with longer black hair ; lateral extreniities of first (visible) tergite 

 paUid neutral grey pollinose (posterior angles faintly pinkish-buff) and clothed with 

 whitish hair, lateral extremities of following five tergites whitish pollinose, clothed 

 with glistening whitish or silvery white hair, which towards and on hind margins of 

 posterior segments ma}^ merge into glistening Naples yellow hair ; dorsum, except as 

 stated, clothed with minute, appressed black hairs ; venter, except last segment, 

 cinnamon-drab or light cinnamon-drab, with a more or less distinct though not sharply 

 defined median, quadrate, mummy^brown blotch (resting on front margin but not 



