158 [July. 



simultaneously dropped the prey, cleaned her proboscis and took Hij^ht. 

 This was the usual procedure, but on four occasions the male after 

 uncouplinfr, carried away the prey, which he helps the female to 

 support with his posterior tarsi during copulation. In no case did 

 the female ever retain the prey after the male had uncoupled. During 

 the whole period of copulation the male moves his abdomen, more 

 especially the posterior segments, backwards and forwards with a 

 regular rhythm, this part of the body being alternately telescoped, 

 and expanded for a small fraction of its length. 



E. tessellata, F. — The following observations relating to this 

 species were made at Lye Hill, near Cowley, Oxford, on May 23rd 

 29th, 30th, and June 5th, of the present year. On each occasion the 

 species occurred in abundance, being like E. opaca most active 

 during bright sunshine. 1 have seen them pairing as early us 10 a.m., 

 and as hite as 5 p.m. The males of tessellata fly much higher than 

 those of E. opaca (often quite out of reach of the net) ; they also 

 keep closer together, flying backwards and forwards very swiftly, 

 frequently approaching and touching each other, as if testing for the 

 pcesence of females, which when discovered are immediately chased by 

 one or more males. The subsequent pairing and manner ot holding 

 female and prey being identical to that of E. opaca, it is unneccessary 

 to repeat the details. After pairing they retired into the deep shade 

 in the interior of the high hedge, so that the relative number found 

 in copula is very small as compared with the number seen to pair. 

 At 3.50 p.m., on May 29th, a male and female were observed to pair 

 and settle down, the male, as usual, hanging by his two anterior legs 

 to the edge of a leaf. They were at once enclosed, leaf and all, in a 

 large glass-bottomed box, without the least disturbance ; the box was 

 placed in the shade and the insects watched during the entire period 

 of copulation. The female, during the whole time, kept turning and 

 twisting the Dipterous prey, and continually thrusting her proboscis 

 into a fresh place. When the victim is examined with a lens the 

 punctures made by the female Empid are clearly visible and arc 

 remarkable for the regularity with which they are disposed over the 

 surface of the body. At 4;. 9 the male uncoupled, the female 

 immediately drop[)ing the prey. On several occasions the male was 

 observed to capture the prey and afterwards disable it. The method 

 adopted was as follows : the male sits in wait upon leaf or grass-stem, 

 darting upon any fly coming near enough. If successful he immedi- 

 ately proceeds to hang by the tarsal claw of one of the anterior legs, 

 to the edge of a leaf or twig, &c., the other live legs being tightly 



