Mishnayos Taharos Perek 5 Mishnah 1

השרץ (creeping thing) – the creeping animal defiles through contact but not by lifting (see Tractate Kelim, Chapter 1, Mishnah 1 as well as Leviticus 11:29-30).

צפרדע – a ritually pure [frog], but since it is similar to a species of lizard and they (i.e., the Rabbis) erred concerning it, because of this, it (i.e., the Mishnah) took [the word] צפרדע/frog.

כזית מן המת -defiles in a tent. But a carrion does not defile in a tent.

עצם מן המת – [a bone from a corpse] defiles through movement, but the bone of a carrion is ritually pure.

גוש מבית הפרס וגוש מארץ העמים – they defile through contact and by lifting/carrying but do not defile in a tent.

שני שבילין אחד טמא – that one of them is a grave lying width-wise and fills all of it, and he doesn’t pass through it so that he will not be overshadowed.

האהיל על אחד מהן – we are referring to on an olive’s bulk of a corpse or on an olive’s bulk of a carrion.

הסיט אחד מהם – [on a bone from the corpse or a bone from the carrion, and similarly] a clod of earth from a ritually pure land and a clod of earth from an area in which uncertainty exists concerning the location of a grave or a corpse/בית הפרס and a clod of earth from the land of the nations (i.e., outside the Land of Israel), that defile through movement.

ר' עקיבא מטמא – for Rabbi Akiba holds that defilement in the public domain – its manner of doubt is pure – these words apply when he made/prepared pure things, since they lack any remedy when they are defiled. But concerning a person who is caused to need ritual immersion [in a Mikveh] and sprinkling [of ashes], he holds that he requires ritual immersion and sprinkling, lest today or tomorrow the matter becomes verified that he was defiled.

וחכמים מטהרים – for even a person who has a remedy, we don’t we require him to undergo ritual immersion and sprinkling. And the Halakha is according to the Sages.