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mens approach it but nonę were so brightly particoloured, so smooth, brightly aenescent, and rounded as is the South Euro-pean insect. The majority of the specimens were of the var. siculus type and the remainder were near to var. fowleri.

Orecłochilus uillosus Muli. 1776

Size of O examined 6,0 x 2,5 mm.

L o c a 1 i t y:—Krzemieniec riv, Ikwa, 14, VIII. 1923, 1 y,

Very convex; labrum projecting, fringed with long setae; pronotum and elytra very finely reticulate, with numerous irre-gular deep punctures and a fine pale yellow pubescence; no elytral striae. Upper surface fuscous, often almost black, with margins of prothorax and elytra yellow, antennal socket and antennae yellow; under side, legs and tarsal claws pale yellow.

This species, owing to its pubescence and the absence of elytral striae, cannot be confused with any species of Gyrinus. There is a variety, var. bellieri Rche, which has the under surface fuscous and a sub-species inuohens Fałd. which is larger (6.5—9.0 mm). For a discussion of this variety OcHS, 1929, (Zu dem Thema Orecłochilus involvens Fałd. und Orecłochilus zerau-schanicus Glas. Ent. Nachrichtsblatt Bd. III, Hft. 2, pp. 46—47),

should be consulted.

S u m m a r y.

The Gyrinidae are except,ionally highly specialized insects adapted to a difficult environment. They differ from other Adephaga on this account. The similarity in the larvae shows them to be related to the Dytiscidae. The two stocks, however, separated before the imago had become adapted to an aąuatic habitat. The Dytiscidae and Gyrinidae can therefore be placed side by side as Families of the Sub-Order Adephaga and the Tribe Hydradephaga. The Polish materiał indicates that in the north species become morę densely pigmented and larger and that this is due to Iow temperaturę. It also throws light on the composition of the G. nałałor-subsłriałus-suffriani species-com-plex.

From the Zoological Department, Armstrong College,

University of Dnrham, England.

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