[4] Journal of the Quekett Microscopical Club, v. 148.

[5] Ponds and Rock Pools, p. 17.

[6] Bulletin of the Illinois State Laboratory of Natural History, iv. 158.

[7] ‘Dytiscus’ is written of set purpose. It is not, as some people tell us, a miswriting for Dyticus; but a properly formed diminutive, from the Greek dutēs = a diver; like paidiskos = a little boy. Linnaeus consistently calls the genus Dytiscus from 1735 onwards. Dyticus only dates from Geoffroy’s Histoire Abrégée des Insectes, first published anonymously in 1762. On this question of nomenclature I am glad to have the support of the Rev. T. R. R. Stebbing, F.R.S., who, in answer to my inquiries, kindly wrote, ‘Darwin uses “Dytiscus” in the Origin of Species, and I should decidedly recommend its being upheld.’

[8] April 4, 1896.

[9] Popular History of the Aquarium, p. 258.

[10] May 2, 1896.

[11] International Science Series, No. lxv.

[12] Aquatic Insects, pp. 55, 56.

[13] Zeitschrift f. wiss. Zoologie, Bd. xl. S. 481.