40 MEMOIRS OF THE CARNEGIE MUSEUM 
average measurements being about fifty centimeters in length and thirty centimeters 
in breadth. At Las Guacas, however, | measured broken specimens of the immense 
size of one and a half meter in length and sometimes of a meter in width, and I also 
encountered diminutive specimens, like those figured on PI. III, Figs. 1, 2. The 
latter undoubtedly were made for children. The breadth of the plate in the group 
with cylindrical legs is, as a rule, proportionately much larger than in the latter. 
In the former group by far the greatest number of specimens are plain without any 
ornamentation. Of the forty-nine specimens of this group, which I encountered 
during my excavations, thirty-three were plain, two decorated only on the upper 
side at both ends with a broad band with geometrical designs, four had similar 
decorative bands on the under side, either at both ends, or enframing the whole sur- 
face, six were decorated with bands on both the upper and lower sides, while four 
showed the enframed under side filled up with representations of highly conven- 
tionalized animal or human forms or with geometrical designs. The ornamentation 
of the cylindrical legs is prevalently limited to the lower end and is simply annular 
or composed of vertical grooves. ‘The cylindrical legs are never perforated. 
The second group having the flattened triangular legs, although much smaller, 
is the most interesting and most highly artistic. Though I myself found only three 
examples, I encountered in the burial-ground numerous scattered fragments of this 
type, and from Padre Velasco I secured a number of the best specimens which he 
had obtained. As has been observed, these metates are generally rather small in 
size and with a narrow plate, the average measurement being fifteen by seven centi- 
meters. The plate is even and curved upward before and behind, but never hol- 
lowed out, or dished. They are cut from the most finely grained basaltic lava, and 
display in common several peculiar features, as has already been shown in the speci- 
mens described. Only a few specimens more crudely made are devoid of ornamen- 
tation, but most of them show lavishly rich sculpturings, many being, except on the 
two-thirds of the upper side of the plate which is used for grinding, entirely covered 
with ornamentation. ‘These ornaments are of a different character from those found 
in the larger group. On the upper side there is usually a very broad rectangular 
field at the front end and only a narrow band at the back. While in the former 
group the geometrical design of the band consists of a guilloche or meander pattern, 
in this group a peculiar plaited or woven pattern of several variants prevails. The 
narrow edges of the borders of the plate in this group are, as a rule, covered with a 
meander design, while they are never decorated in the former group. The under 
side is usually covered with a plaited or highly conventionalized anthropomorphic 
design. Metates of this group often were evidently intended to represent in general 
