18 Mr. C. H. T. Townsend on Diptera 



as well as tlie veins and wliole wing - surface, especially 

 noticeable being various rich shades of blue and violet. 

 Poey remarks at some length on this peculiarity (Mem. Hist. 

 Nat. Cuba, i. p. 240 : Havana, 1851). When the wing is 

 held up to the light and looked through, the dark spots 

 appear faint, excepting only the elongate rectangular black 

 stigma ; this can be seen with the naked eye. 



StratiomyidaB. 



2. Sargus, sp. 



One specimen, June 19, San Rafael. Taken from an 

 attid spider which had captured it. 



Length 10 millim. 



Eyes not contiguous. Front deep metallic green on 

 posterior two-thirds, pale yellowish on anterior third. Thorax 

 and scutellum deep metallic green, with purplish reflection 

 on dorsum. Abdomen black, with hind borders of segments 

 broadly shining violet or ])uvplish. The black of abdomen is 

 soft opaque in some lights, and shining in others. Wings 

 scarcely tinged with fuscous. Legs pale yellowish, middle 

 femora broadly brownish in middle, hind femora blackish 

 except bases and tips, hind tibia3 black on distal half, and 

 hind tarsi blackish except basal half of metatarsi. 



Tabanidae. 

 3. Chrysojjs costatiis, Fabr. 



One female, March 16, San Rafael. 



Length 7^ millim., not including antenna?. 



The eyes in life are green, Avith brown-black markings. 

 There are four brown-black, rather quadrangular spots on 

 anterior portion of eye, arranged in the shape of a diamond, 

 with the long axis vertical. The posterior spot of the four 

 is longitudinally elongate, occupies very nearly the centre of 

 the eye, and is bisected by a vertical brown-black linear 

 stripe extending from the upper to tiie lower margin of the 

 eye. Tiie anterior spot is nearly square, while the other 

 two (upper and lower spots) are transversely elongate. In 

 addition to these four spots, there is a vertical bronzed line 

 near ])osterior edge of eye and parallel with the hind margin, 

 extending from upper to lower border. 



Annulate portion of third antennal joint black, the distal 

 part of basal non-annulate portion tinged with blackish. 

 The non-annulate portion of third joint is rather distinctly 



