34 A STUDY OF CHIRIQUIAN ANTIQUITIES. 



ends of the grinder on either side." This was made possible because the 

 metate's grinding surface was flat in the transverse direction and not bounded 

 by a raised rim. 



The Chiriquian grinding stone had to fit a very different sort of grinding sur- 

 face - - one concave in both directions and bounded by a low rim. The upper 

 stone, therefore, is relatively short. An example is reproduced on its metate 

 (see fig. 17). It resembles a flattened cylinder, rounded at the ends. Another type 

 is nearly rectangular in section, with flattened ends. The stone reproduced in 

 figure 31 is a good example. It fits one of the metates in the collection (see 

 fig. 27), but may not have been found with it. 



There is a single specimen that would seem to be better adapted for use in a 

 mortar than on a metate (fig. 32). It may have served as a grinding stone for 

 the small metates with high square rim (see fig. 26) or the so-called stone stools 

 with circular tops (see PI. IV, fig. e). In shape it may be compared to an inverted 

 toadstool. A similar type of pestle has been found in southern Indiana and Ohio, 

 as well as on the northwest coast of America. 



Fig. 31. Fig. 32. 



Fig. 31. Rectangular rubbing stone. V 

 Fig. 32. Pestle. '/ 



Fig. 33- 

 Fig. 33. Sub-spherical pestle streaked with gold. 



A cylindrical hammer stone with tapering and battered ends should be mentioned. 

 One of the most interesting stone implements of the collection is a sub-spherical 

 pestle with polished surfaces and almost everywhere streaked with gold (fig. 33). 

 De Zeltner, from whom the specimen was bought, believed it to have been used 

 by the natives to reduce the gold to powder preliminary to the process of fusion. 

 It was entered in his catalogue as a " pierre de porphyre, forme de boulet un 

 peu equarre ayant servi de marteau d'or, on voit encore les traces du metal." 

 This is the specimen referred to by Gabriel de Mortillet 1 as "ayant servi a triturer 

 le metal afin d'en faciliter la fusion." The stone is of volcanic origin, probably 

 a well-cemented ash or tuff. 



1 Materiaux pour 1'histoire primitive et philosophique de I'homme, IV, 65, J868. 



