48 MEMOIRS OF THE CARNEGIE MUSEUM 
tured at one end, was encountered here, and was for some time in the possession of 
Velasco. ‘Two typical specimens of the cylindrical stones are illustrated. 
(a) (Pl. V, Fig..2.) Grinding stone of basaltic lava. Excavated by the writer 
at Las Casitas, now in the Stockholm Museum. Length 47 cm. 
(b) (Pl. V, Fig. 3.) Grinding-stone of the same material. Excavated at Las 
Guacas by Carillo, and now in the Stockholm Museum. Length 56.8 cm. 
2. Stirrup-shaped Grinding-stones. 
Only a few specimens of this singular, highly developed form of grinding-stone 
have been found at Las Guacas. When using this tool the worker grasped the side 
bars with both hands, the thumbs resting on the top bar. Several metates on which 
only these, or other small, simple, grinding-stones with a convex base could have 
been used, have been encountered at Las Guacas. One similar metate, which I ex- 
humed, is illustrated on Pl. III, Fig. 5. The stirrup-shaped form of rubbing-stone 
has been encountered in a few localities in the highlands also, as on Irazu, and by 
me at Orosi. (See Pl. 69, Fig. 1, in “‘ Archeeological Researches in Costa Rica.”) In 
1896 I discovered some specimens during excavations at Carrizal near Puntare- 
nas. Nowhere in Costa Rica has this form been found in any number. The center 
for its distribution is still unknown. Some specimens are illustrated on Pl. XXII. 
They are all made of basaltic lava. . 
(a) (Pl. XXII, Fig. 6.) Grinding-stone, ornamented with five knobs on the top 
bar, the central opening oval, base slightly curved, convex, showing wear from use. 
Height 13.8 cm., breadth 14 cm. (Cat. No. 242$.) 
(b) (Pl. XXII, Fig. 4.) Grinding-stone with two opposing human heads sculp- 
tured on the top corners. Base curved, convex, central opening almost rectangular. 
Found at Aguas Calientes in the highlands. Reproduced for comparison. Height 
15 cm., breadth 15 em. (Nat. Mus. of Costa Rica.) 
(c) (PI. XXII, Fig. 3.) Grinding-stone with a small bird on the top bar. Base 
almost straight, convex, central opening nearly square. Height 12.2 cm., breadth 
11.7 em. Found in Nicoya. (J. Cooper.) (Nat. Mus. of Costa Rica.) 
(d) (Pl. XXII, Fig. 2.) Grinding-stone with saddle-shaped top bar, the ends of 
which are each adorned with a human head. Base curved, convex. Height 13.5 
em., breadth 14.5 cm. Found at Aguas Calientes (?) in the highlands. (Nat. Mus. 
of Costa Rica.) 
(ce) (Pl. XXII, Fig. 1.) Grinding-stone, representing a highly conventionalized 
human face with head ornament. The head-dress is composed of two opposing 
animal heads. Compare with the ornamentation of celt-shaped amulets (PI. 
