This last, however (Plates XI. and XII.), represents another variety of
earth-house, the chambered mound or beehive, with an underground gallery
leading to it. Of this kind two examples are here shown. And in Plates
I. and XIII. will be seen specimens of wholly subterranean structures.
It is difficult, and indeed hardly necessary, to distinguish between one
variety and another of what is practically the same kind of building;
but to this last class the term "earth-house" is most frequently
accorded in Scotland. In the broader dialect it is "yird-house" or
"eirde-house," which at once recalls the form "jord-hus" in the saga
which tells of Leif's adventure underground in Ireland. The term _weem_
is also applied to these places in Scotland. This is merely a quickened
pronunciation of the Gaelic _uam_ (or _uamh_), a cave; and it reminds
one that, both in Gaelic and in English, the word "cave" is by no means
restricted to a _natural_ cavity. Indeed, one of the two artificial
structures under consideration is known as _Uamh Sgalabhad_, "the _cave_
of Sgalabhad." Another old Gaelic name for those underground galleries
is "_tung_ or _tunga_";[61] while another name, by which they are known
in Lewis is _tigh fo thalaimh_,[62] or "house beneath the ground."

"Martin, in his description of the Western Islands, printed in 1703,
when their use would appear to have been still remembered, speaks of
them [these underground structures] as 'little stone-houses, built under
ground, called earth-houses, which served to hide a few people and their
goods in time of war.'"[63] Dean Monro writes, "There is sundry coves
and holes in the earth, coverit with hedder above, quhilk fosters many
rebellis in the country of the North head of Ywst" [North Uist].[64]
"From O'Flaherty's description of West Connaught, written in 1684, it
appears," observes Captain Thomas,[65] but referring more strictly to
the beehive-house, "that this style of dwelling had already become
archaic." For, although that writer mentions certain "cloghans" as being