374 Professor E. B. Poulton on 



An observation on the crj/ptic attitude of Asilus crahroni- 

 foTDiis during prolonged rest. 



As this Memoir contains certain miscellaneous observa- 

 tions upon the Asilidi&, such as the notes upon the court- 

 ship of Dasgpogon {Selido2Jogon) diadema on pp. 366-368, 1 

 have thought it worth while to include the following. On 

 the evening of July 28, 1906, I observed a female of this 

 species at rest on a head of Ccntaurea scahiosa. beside 

 the footpath leading to Stone's Copse, above North 

 Hinksey, near Oxford. The insect had evidently gone to 

 rest for the night and was quite torpid. The appearance 

 strongly suggested a roUed-up crumpled brown leaf or leaf- 

 fragment which had accidentally fallen upon the flower. 

 This cryptic resemblance was brought about by a remark- 

 able attitude, the insect being precisely in the position 

 formed by a half somersault, — arrested when the ventral 

 surface was uppermost. Hence the closely-folded wings 

 and the conspicuous gold and black bands were entirely 

 invisible from above ; the only appearance being that of the 

 brown shades on the legs and ventral surface. The colour- 

 ing of these was so beautifully adapted to produce the 

 cryptic effect suggested above that I think it is probable 

 that I witnessed a single example of an attitude commonly 

 assumed by the species during prolonged rest. 



Lojjhonotics (two species), Nos. 157-162. — Hymenoptera 

 contribute half of the six victims recorded for this genus. 

 The list is as follows : a Dragonfly, a beetle, a Geometrid 

 moth, two Fossorial wasps, and a Chalcid. Some preference 

 for Hymenoptera may be regarded as probable. 



JJysmachus (Nos. 163-174). — Five species have been 

 discriminated by Col. Yerbury and Mr. Verrall in the 

 material upon which this paper has been prepared. (See, 

 however, note on p. 350.) They differ but slightly in size 

 and superficially resemble each other in appearance. 

 Twelve examples are tabulated, the prey belonging to the 

 Coleoptera (3 Melolonthids, 1 Coprid), Lepidoptera (1 Geo- 

 metrid, 2 Crambids), Diptera (1 Stratiomyid, 1 Empid, 1 

 Anthomyid), and Hymenoptera (1 Ichneumon, 1 winged 

 ant). At first sight the selection seems entirely indis- 

 criminate and haphazard, but when regard is paid to the 

 circumstances of the case it is found that choice was 

 exercised at least in one case. When I captured the 

 three specimens (Nos. 169, 170, 172) with Melolonthid 



