Of these are formed composite groups d, which belong, however, to the system of round signs.
Other analogous but not identical signs appear to assume rather the ovoid form than the round, and seem to have been so traced as not to be confounded with the round symbols. Some of them resemble leaves or fruit.
Another system of simple characters is the straight line, which can be represented by a stroke of the pen, isolated or repeated as if in numeration, and sometimes accompanied by other signs.
Other peculiar signs shown in e, which are not repeated, figure in the different groups of characters which the author has reproduced.
We notice further, in f, a small number of signs which bear a certain analogy to each other, and several of which are accompanied by other and more simple characters.
Several others still more complicated are in eccentric shapes which it is attempted to present in g.
Including the common oval characters often repeated and those consisting of a simple stroke similar to the strokes made by school children, all the various engraved characters scarcely exceed 400.
Fig. 145 gives a view of a series of different groups of signs in the length of the whole lava flow. The copyist has expressed by dots those symbols which were confused, partly defaced by the weather, or destroyed by fissures in the rock.
Fig. 145.—Petroglyphs in Canary Islands.