=Methods of Collection and Preservation.=--Woodlice should be collected straightway into tubes or bottles half filled with 30 per cent. methylated spirit.[3] Woodlice dropped into this weak spirit become gradually narcotised and die, and they remain limp enough for purposes of examination or to allow, of their legs and antennæ being set out during the process of mounting. Specimens to be kept permanently should be placed in 70 per cent. alcohol. For storage purposes the specimens of each species from a given locality should be put together into a small flat bottomed tube such as is used for pillules by apothecaries or specially made for natural history purposes. A paper label on which the name, locality, date of capture and any other necessary particulars have been written with dark lead pencil, is not affected by the spirit. The tubes may be corked, though if not frequently examined all the spirit may evaporate, and cause the specimens to be spoilt. A safer method is to plug the tubes with cotton wool and keep all those containing a given species or specimens from a particular locality beneath the surface of spirit in a large wide-mouthed bottle, into which first of all some cotton wool has been put to prevent the tubes from coming into sudden contact with the glass at the bottom. For show purposes in museums, specimens taken direct from 30 per cent. spirit should be mounted on slips of opal glass by means of gum-tragacanth which has been powdered and shaken up in spirit before having water added to it. The slips can be exhibited in glass tubes, six inches high by one across, or in narrow stoppered museum jars. A variation of the method is to mount the animals on clear glass and to place behind them another strip of any colour that may be preferred. =Classification.=--The various genera of woodlice are connected together so closely, by intermediate forms, that their division into families is, to a very great extent, arbitrary. Bate and Westwood described but a single family Oniscidæ (I), though they distinguished two sub-families:--Ligiinæ, which included the forms with many joints to the flagellum of the antenna, and Oniscinæ, which contained the rest. Since then the pill-woodlice have been thought by some to be sufficiently different from the other genera to warrant their separation, and three families namely, Ligiidæ, Oniscidæ, and Armadillidæ have been recognized, as for instance by Dr. Scharff (63). A fourth family--Trichoniscidæ--has been added by Professor G. O. Sars, who in his _Crustacea of Norway_ (59) alludes to the division of the tribe into the sections Ligiæ and Onisci and has adopted the following classification:-- _Order_--=ISOPODA.= _Tribe_--ONISCOIDA. _Family I._--LIGIIDAE. _Ligia._ _Ligidium._ _Family II._--TRICHONISCIDÆ. _Trichoniscus._ _Trichoniscoides._ _Haplophthalmus._