now contains only 6 British species. The principal distinction 

 of this group is the incrassated anterior thighs, which in the 

 remainder, named by him Platypalpus, are more slender than 

 the middle pair : I find that they are serrated beneath in the 

 Tachydromiae, and the tibiae spined on the inside, which he 

 has overlooked: the intermediate tibiae are simple: the trans- 

 verse nervures also in Tachydromia are straight, whereas they 

 are oblique in the other group; the palpi and antennae are 

 likewise different; but the latter vary very much also in Pla- 

 typalpus. These insects, like the Empidae, seize and live upon 

 other Diptera, for I have myself several times detected them 

 feeding upon small flies. 



The Tachydromiae run with great swiftness, with their wings 

 lying on their backs; and being prettily marked, they have 

 the appearance of some of the small Cimicidae (Gen. 1100. 

 Phytoceris, &c.). I shall translate the specific characters 

 from Meigen. 



1. T. arrogans Linn. — Curt. Brit. Ent. pi. ^T?. 9- — cimi- 

 coides Fab. 



Found near London ; b. June, on a wall and felled timber 

 in abundance, in the New Forest; end of July and middle of 

 October, Isle of Wight. J. C. 



I have drawn this pretty insect, because nothing can be 

 more interesting to the naturalist than to identify the Linnaean 

 species ; and it is remarkable that no figure of it should have 

 been hitherto given. 



■2. T. annulimana Meig. 3. 69. 2. " Black shining; anterior 

 thighs rufous, with 2 black rings; base of the tarsi ru- 

 fous; wings with 2 fuscous fasciae. \\ line." 



Taken with the former. 



3. T. connexa Meig. 3. 70. 3. tab. 23./ 24. Black shining; 



anterior thighs entirely, and posterior with the base, 

 rufous; wings with 2 broad fuscous fasciae, united at 

 the costa. 1 line." 

 Taken by Mr. Walker at Southgate. 



4. T. fuscipennis Fall. — Meig. 3. 71. 5. "Black; antennae 



and legs ochreous ; wings fuscous, apex white. 1 j line." 

 4*. T. nubila Meig. 3. 71- 7. " Black, wings cinereous; legs 

 variegated with black and yellow. 1^ line." 

 My specimen was, I believe, from Hampshire. 



5. T. nervosa Meig. 3. 72. 8. " Black, wings hyaline, 'nervures 



fuscous; legsvariegated with yellow and fuscous, lline." 

 I observe the eyes are contiguous in front in the female. 

 Near London; end of May, Netley Abbey; beginning of 



June, New Forest; middle of October, Isle of Wight. 



The Plant is Senecio sqaalidus (Inelegant Ragwort), froin 



walls in Oxford. 



