INSECTS 



occurrence in situations apparently far away from any colony of the wild 

 bees at whose expense it has passed its early stages, is not easily accounted 

 for. 



Turning now to the water-beetles, we shall find the whirligig beetles 

 {Gyrinida) conspicuous by reason of their numbers, and interesting on 

 account of their structure. These insects are known to all from their 

 habit of floating lightly on the surface of the water, and performing 

 graceful complex curves round one another, apparently without colliding. 

 They are admirably constructed for a mode of life which is comparatively 

 rare in the insect world. They have four eyes, one pair on the upper 

 surface and another on the lower, and very short antennas which can be 

 packed away in the space between the upper and lower pairs of eyes on 

 each side of the head. They are able to dive to escape danger, and then 

 carry with them a small supply of air under the wing-cases, from which 

 a portion of it protrudes as a bright silvery bubble, but they do not stay 

 long beneath the surface. When handled they exude a milky-white fluid 

 which has a very disagreeable smell. Their two hind pairs of legs are 

 beautifully modified so as to serve as paddles, expanding when moved in a 

 backward direction and collapsing into an extremely small space directly 

 the resistance they meet with is in the other direction. The construction 

 of their fore feet is very peculiar. In other water-beetles the soles of the 

 fore feet are directed downwards, but in the whirligigs the fore legs are 

 so set on that the soles of the fore feet are not turned downwards, 

 but towards one another, and the assemblage of suckers which constitutes 

 the prehensile apparatus proper to the soles of the fore feet in the males 

 of water-beetles is in these carried on what is really the side of the fore 

 foot and not the sole. As might be expected from its physical features, 

 Norfolk is especially rich in Gyrinidce^ nine out of the eleven kinds known 

 as British having already been found there. Some of the species congre- 

 gate in immense numbers in the open water near the banks of rivers, 

 whilst others perform their gyrations in the shelter of the stems of water- 

 plants, and are rarely seen except by entomologists in search of them. 

 In some kinds, as Gyrinus elongatus^ found in ditches near the coast, 

 and G. bicolor, a denizen of Hickling Broad, a small percentage of in- 

 dividuals are of a diff^erent form to the others, being quite parallel-sided ; 

 whether this abnormal form is of advantage or otherwise to the in- 

 dividual does not appear. 



In the following list the names of the captors or recorders of species 

 when other than the author are given after each entry. The ento- 

 mologists referred to are : C. C. Babington, F.R.S., Professor of Botany 

 at the University of Cambridge ; T. Hudson Beare, F.E.S. ; Alfred 

 Beaumont, F.E.S. ; E. C. Bedwell, F.E.S. ; W. G. Blatch, F.E.S. (ob. 

 1900) ; J. B. Bridgman, F.L.S., F.E.S. (ob. 1899) ; Thos. Brightwell, 

 F.L.S., formerly of Norwich ; the Rev. J. Landy Browne of Norwich ; 

 the Rev. John Burrell, A.M., F.L.S., F.E.S., Rector of Letheringsett (ob. 

 1825) ; E. A. Butler, F.E.S,, ; G. C. Champion, F.Z.S., F.E.S. ; the 

 late Rev. Hamlet Clark ; the late G. R. Crotch ; the Rev. C. T. 

 I 113 I 



