10 BUREAU OF AMERICAN ETHNOLOGY [Bull. 177 
content under each Phase is purely descriptive. AJl of the archeolog- 
ical data resulting from fieldwork and laboratory analysis of the 
materials collected are included. 
For the reader interested mainly in the overall results, there are two 
principal places to look: the conclusions to each geographical section 
(pp. 28-24, 145-153, 183-190, 326-332) and the last chapter of the 
volume (pp. 333-347). The final chapter on the cultural sequence 
in British Guiana summarizes the general conclusions and appraises 
their significance not only in archeological terms but also in terms of 
anthropological problems of various kinds. The reasoning upon 
which these statements are based can be found in the conclusions to 
each of the four major sections of the report. Here, archeological, 
ethnographic and historical data are brought to bear on the problem 
of reconstructing the origin, duration, and nature of each of the 
archeological phases and through this the prehistory of the region. 
Presentation of the data follows generally accepted lines of current 
archeological monographs and needs no detailed explanation. We 
would like, however, to say a few words about the methods of analysis 
and classification used for the artifacts. Whenever possible, the arti- 
facts are described as types showing their range of variation as well 
as their most typical features rather than as individual specimens. 
It has been our experience that this is not only the most practical 
method of dealing with a large bulk of material, but also it objectifies 
and clarifies the data and makes the results easier to assess. Unfor- 
tunately, stone tools usually were not sufficiently abundant to permit 
the substitution of type descriptions for the description of each ex- 
ample, but where possible this has been done. All pottery was classi- 
fied into types, and those few sherds that were distinctive but rare 
were called “unclassified” and not given type names. 
The theory of pottery type classification has been set forth by many 
others (e.g., Ford, 1949, pp. 38-44; 1954; Krieger, 1944; 1949, pp. 71- 
80; Spaulding, 1953) and there is still much controversy about which 
system is the “best.” This report is not the place to debate the issue. 
However, in order to leave no confusion in the mind of the reader 
about our purpose or procedure, we will describe briefly the steps 
followed in handling the pottery. The principal reason for making 
pottery type classifications is, in our opinion, to detect significant 
differences that will permit the recognition of cultural and temporal 
change. Consequently, the first question we ask in beginning the 
classification of a new batch of sherds is, “Are there any readily ob- 
servable differences?” From extensive experience with sherds from 
Tropical Forest cultures of South America we have discovered that 
temper differences are often easily distinguishable and generally re- 
flect change through time. Thus, we first attempt to classify the 
