altiKisl wholly composed of tjic («yt*H, uliirli, with few- exceptions,* 

 iiU't't totirthti' aho\r in tluit sex. hiif in tii«- Innair arc separated 

 by tlie space known as the front, hearing in ('hry,s(>i).s, Tahanu.H, and 

 Ild'nuttopota a shining spot or rdlliis, tlic siiape and coloration of 

 which alYoril usct'ul specific- characters. The males have an area in 

 the np])er portion of the eyes, varying in extent according to the 

 species, comiiosed of LiiLrci' facets than those heiow ; this dilTerence 

 is as a iiile well-marked in the '!'al)anina>, hut is often less consj)icuous 

 in species of Paugonin or Chrysops. In the li\ing insects the eyes 

 of the majority of 'Pahanidic are singularly heaiitiful, heing often 

 golden-green, coppery-green, hlue, or brilliantly metallic iridescent, 

 marked with i)in'ple or brown hands or spots ; these eye-markings 

 are of \aliie for the identification of sj)ecies, and arc especially 

 brilliant in tlu^ case of females of Chrysops and /Itrni/ttopoUi, which, 

 as remarked by Girschner,f " possess probably the finest eyes of 

 all insects." After death, however, the colour of the eyes rapidly 

 changes to a dull brown or brownish-black, until little or no trace 

 of the markings re mains. J 



Fn all Tabanidai tiie three-jointed antennae, which in the genus 

 Chrysops attain a considerable length, project conspicuously in 

 front of the head. In Tdhdiius and Hmmatopoki the proboscis 

 (labium), which contains the piercing mouth-parts, is soft and fleshy, 

 of moderate length, terminated by a pair of laige and consjiicuous 

 labella, and depends vertically beneath the head. In C/irysops 

 the proboscis, which is still vertical, is more slender and often 

 distinctly elongate ; while in Pangnyiin {sens, hit.) it is strongly 

 chitinised, generally slender, and often hori/,ontal in position and 

 remarkably long, sometimes even considerably exceedmg the body 

 in length. The palpi, one of which can be seen on each side of the 

 base of the proboscis, are two-jointed ; the terminal joint, which 

 differs in shape in the two sexes, is usually swollen and fleshy in the 



* In certain species of C'hry.wps, c.t)., Ch. lotiyicorniti, Macq., and Ch. fu.irn. 

 Ricardo, the eyes are narrowly separated above in the male. 



t Cf. E. Qirsclmer, Berliner Entomologische Zeitschrift, Bd. XXXI.. p. 150 (18S7). 



X III the figures ilhistrating this witrk the eyes are shown as seen in dried 

 specimens, from which tlio drawings hati noco!*.sarily t<i Ix» prepared. 



