Concerning the first 2 postulated cultural epochs (Table 2) the Pre-Agricultural and the epoch of Incipient Agriculture, our evidence is limited, sometimes contradictory, and generally hypothetical. However, in the ease of the San Nicolás site there is positive proof of an hitherto undescribed lithic culture which is seemingly preceramic and pre-agricultural. For present purposes we will briefly present this evidence under the more noncommittal heading of preceramic evidence.