ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 693 



Cockchafer-years.*— J. E. V. Boas points out that in Denmark the 

 cockchafer (Mdolontha vulgaris) lives for four years, and of the four 

 different stocks, which thus live in Denmark, the one appearing as imago 

 the year before leap-year (1887, 1891, etc.) has been for many years the 

 most numerous. The numbers have been so apalling that " great cock- 

 chafer years" are remembered as disastrous. Since 1887 there has 

 been diligent collecting, and the author gives full statistics showing how 

 the numbers have waned in a remarkable way. There are no longer 

 "great cockchafer years." As in other cases there has been a pro- 

 gressive dwindling, the cessation of the plague being probably due to a 

 bacterial disease. It is to be feared, however, that there will be a return 

 after a series of years has elapsed. The author's report is interesting 

 biologically as well a3 economically. 



Variations in Hydrophilus piceus.f — Umberto Perazzo has made 

 a careful study of the variations in this water-beetle, and gives a long 

 series of measurements, without, however, as yet drawing any conclusion. 



Diptera, etc., of Uganda.^ — E. E. Austen gives a provisional list of 

 the Diptera and other orders of insects, besides two species of ticks, 

 Amblyomma sp. and Ornithodoros moubata Murray, forwarded by Lieut.- 

 Col. Bruce from Uganda. 



May Flies and Midges of New York.§— J. G. Needham gives an 

 account of the Ephemerida?, K. J. Morton of the Hydroptilidas, and 

 V. A. Johannsen of the aquatic nematocerous Diptera — the whole form- 

 ing the third report on aquatic insects published by the New York State 

 Museum, a valuable and finely illustrated piece of systematic descriptive 

 work. 



New Chironomid.|| — B. Grassi describes Mycterotypus bezzii g.et sp.n., 

 a new Indian Chironomid. The new genus replaces Centrotypus Grassi, 

 and is included in Skuse's sub-family Ceratopogonina. 



Structure and Life-History of Psychoda sexpunctata.lf —J. A. Dell 

 gives a careful account of this fly, one of the Nemocera, which abounds 

 on the coke-heaps at Leeds Sewage Works. He describes the nervous, 

 alimentary, and respiratory systems of the larva, the features of the 

 pupa, and the general characters of the adult. We select the paragraph 

 which describes the sexual union : — " In copulation the male runs along- 

 side the female, stroking her with his antenna?, while the wings, antenna?, 

 and halteres are thrown into spasmodic vibration. The large forceps is 

 then extended directly backwards, and the abdomen of the male bent 

 round so that the hinder ends of the two bodies are brought into 

 apposition. The forceps then close upon the body of the female, unless 

 they miss, which not infrequently happens, as the male fly is unable to 

 see what he is doing. In such a case the whole manoeuvre is repeated. 



* Oldenborremes optrseden og udbredelse i Danmark. 1 887-1903. Large Ito, 

 Copenhagen, 1901, 24 pp., 5 large maps. 



t Atti R. Acad. Sci. Torino, xl. (1905) pp. 1089-1106. 



X Royal Society's Reports, Sleeping Sickness Commission, No. 5. July 1905, 

 pp. 3-7. § Bull. 80, New York State Museum, 1905, pp. 1-331 (37 pis.). 



|| Atti (Rend.) R. Accad. Lincei. xiv. (1905) pp. 114-21) (4 figs.). 



*! Trans. Entomol. Soc. London. 1905, pp. 293-31 1 (14 figs.)- 



