1909.] 161 



them in the previous year. They were seen by me and Prof. Poulton, to 

 whom T showed them, flying in small companies in the sun, but always 

 under the shelter of a bush or overhanrrino: bough, and every one was 

 carryiniT prey. A number were captured, and with one exception all the 

 examples proved to be males carryingf prey. The single exception, 

 netted because it appeared to be carrying something much larger than 

 usual, proved on examination to be a male, female, and prey. As the 

 public walks in ' The Parks " are not ideal places for prolonged obser- 

 vation, T decided to visit Bletchington again. When T arrived on the 

 ground, about 3 p.m. on May 22nd, T found Pachijmeria in the greatest 

 abundance, every bush or tree having its company. The insects were 

 always seen on the sunny side, so that the bush or tree afforded a dark 

 background. Selecting a small larch for observation, I found that the 

 PncJiymerias could be observed to the best advantage by keeping in 

 the shadow and looking out towards the light. They fly at a fairly 

 uniform height (which varies according to the particular bush or tree), 

 keeping well together and moving or " dancing " in a more or less 

 horizontal plane. In the course of the flight they continually approach 

 and even touch one another. Females, apparently desirous of pairing, 

 joined in the dance, and as soon as one of these was discovered one or 

 more males at once gave chase. They were seen to link together in 

 the air, and soar away to the higher bushes or trees, always well out 

 of reach of the net. Such pairings were seen again and again, but 

 owing to the soaring habit none were actually netted in coitu. At a 

 later date, however, at Lye Hill, two pairs were taken in copula, the 

 female in each case having the prey. The method of resting is quite 

 different from that of the genus Empis, for the female clasps both the 

 twig and the prey, and also carries the male. Many males were boxed 

 with prey as they rested upon twigs, <fec., clasping the victim by their 

 intermediate legs and posterior femora, and the twig with anterior 

 and posterior tarsi. In nearly all cases the prey was carried with its 

 dorsal surface downwards, the pendent wings being very conspicuous. 

 In all cases the victim proved to be Dipterous, and was nearly always 

 as large as, or even larger than the Pacltymeria. 



I have observed these insects at many times and in many localities 

 around Oxford during the present summer, and they were invariably 

 flying and acting in the manner described above. Like some of the 

 other Empids they are very dependent on bright sunshine. Under 

 favourable conditions they may begin their " dancing " as early as 

 9 a.m., and continue as late as 6 p.m. 



Bhaviphomyia sulcata, Fin. — A pair of this species was taken in 



