388 Professor E. B. Poulton on - 
Proportion of the Sexes.—In the recorded A silide it was 
found (p. 359) that females with prey were between three 
and four times as numerous as males with prey. In the 
Empidx tabulated above, such females are almost exactly 
halfas numerous as males carrying prey. In spite of this 
great preponderance of the latter sex, females alone were 
found in 7 species, males alone in only 5, while 4 included 
both sexes. The large proportion of males is entirely due 
to their numbers in only 4 species out of the 15, viz. 
Hybos grossipes, Empis tessellata, Empis livida, and 
Pachymeria femorata. 
Female Empide with prey captured in coitu—This fact is 
recorded frequently in Pachymeria femorata,* twice in 
Eimpis tessellata, Nos. 243, 244, once in ZL. livida, No. 273, 
and once in #. opaca, No. 274. These instances out of 65 
recorded cases form a much higher proportion than in the 
Asilide ; but there are as yet no examples of the female 
attacking the male of its own species or of a remarkably 
cautious pursuit by the male during courtship, to support 
the interpretation which seems inevitable in the former 
group (see p. 367).+ 
The choice of Prey by Empide.—Only provisional con- 
clusions can be reached in all the tabulated species except 
E. tessellata, with 20 records, and £. lividéa with 16. All 
others, except Hybos grossipes (7) and Pachymeria femorata 
(6), are hopelessly insufficient. 
Hybotine.—The 10 records divided between three 
pairs, show an attack upon minute Homoptera, ants and 
Sraconide ; and the Mycetophilide and Bibionide among 
the Diptera. 
Empine.—It is evident that Diptera form by far the 
most important insect food of this sub-family. In fact, 
we find no other prey, except in the case of Rhamphomyia 
* Vide footnote on p. 384. 
+ Kirby and Spence were well acquainted with the facts recorded 
~in the above paragraph, and make amusing suggestions as to their 
significance. Thus we read (5th edition, 1828, vol. i, pp. 274, 
275) :—“ Many species also of Hmpis, whose haustellum resembles 
the beak of a bird, carry off in it Tipularize and other small Diptera ; 
and what is remarkable, you can seldom take these insects in coitu, 
but the female has a gnat, some fly, or sometimes beetle in her mouth, 
Can this be to deposit her eggs in, as soon as they are impregnated 
by the male? or is it designed for the nuptial feast?” No Coleo- 
pterous victim of an Empid is recorded in the present Memoir. On 
the other hand, the predominance of Dipterous prey is abundantly 
confirmed, 
