(b) Menhirs, large single stones, used to mark sight-lines from circles.
(c) Alignments, i.e., lines of stones in single, double, or in many parallel lines. If these alignments are short they are termed avenues.
(d) Holed-stones, doubtless used for observing sight-lines, sometimes over a circle.
(e) Coves. A term applied by Dr. Stukeley and others to what they considered shrines formed by three upright stones, thus leaving one side open. I take them to be partially protected observing places. There are well-marked examples at Avebury, Stanton Drew and Kit’s Coity House.
(f) Cromlechs. This term generally means a grouping of upright stones; it is applied to irregular circles in Brittany. It also applies to a stone or stones raised on the summits of three or more pillar stones forming the end and sides of an irregular vault generally open at one end (“Dolmens of Ireland,” Borlase, p. 429). The top stone is called in S.W. England a “quoit.” Cromlechs in most cases have been covered by barrows or cairns.
(g) Dolmens, from Dol Men, a table stone. These consist of stones, resting on two or more upright stones forming a more or less complete chamber, some of which are of great length. I note the following subdivisions: “Dolmen à galerie” having an entrance way of sufficient height, and “Galgal,” similar but smaller. In the “Dolmen à l’allée couverte” there is a covered passage way to the centre. It is a more elaborate cove. For the relation between cromlechs and dolmens, see Borlase (loc. cit. and p. 424 et seq.).
With regard to dolmens, I give the following quotation from Mr. Penrose (Nature, vol. lxiv., September 12, 1901):—
“Near Locmariaquer in the estuary named Rivière d’Auray, there is an island named Gavr’ Inis, or Goat Island, which contains a good specimen of the kind of dolmen which has been named ‘Galgal.’
“At the entrance our attention is at once arrested by the profusion of tracery which covers the walls. From the entrance to the wall facing us the distance is between 50 and 60 feet. The square chamber to which the gallery leads is composed of two huge slabs, the sides of the room and gallery being composed of upright stones, about a dozen on each side. The mystic lines and hieroglyphics similar to those above mentioned appear to have a decorative character.
“An interesting feature of Gavr’ Inis is its remarkable resemblance to the New Grange tumulus at Meath. In construction there is again a strong resemblance to Mæs-Howe, in the island of Orkney. There is also some resemblance in smaller details.”