(After Montelius.)]

The megalithic monuments of Ireland are extremely numerous, and are
found in almost every part of the country. They offer a particular
interest from the fact that though they are of few different types they
display all the stages by which the more complex were developed from the
more simple. It must be remembered that most if not all the monuments we
shall describe were originally covered by mounds of earth, though in
most cases these have disappeared.

The simple dolmen is found in almost all parts of the country. Its
single cover-slab is supported by a varying number of uprights,
sometimes as few as three, oftener four or more. It is of great
importance to notice the fact that here in Ireland, as elsewhere in the
megalithic area, e.g. Sardinia, we have the round and rectangular
dolmens in juxtaposition (Fig. 5, _a_ and _c_).

[Illustration: FIG. 5. Type-plans of _(a)_ the round dolmen;
_(b)_ the dolmen with portico;
_(c)_ the rectangular dolmen.]

Occasionally one of the end-blocks of the dolmen instead of just
closing up the space between the two nearest side-blocks is pushed back
between them so as to form with them a small three-sided portico outside
the chamber, but still under the shelter of the cover-slab (Fig. 5,
_b_). A good example of this exists at Gaulstown, Waterford, where a
table-stone weighing 6 tons rests on six uprights, three of which form
the little portico just described. The famous dolmen of Carrickglass,
Sligo, is a still more developed example of this type. Here the chamber
is an accurate rectangle, and the portico is formed by adding two