E d 
aanean ARCHEOLOGY IN BRITISH GUIANA 153 
the basis of present evidence. The possibility that the Koriabo Phase 
may have retreated toward the interior is raised by the presence of 
sherds of Koriabo Scraped (pl. 36, f/-2) and Koriabo Incised (pl. 
36, 7) at Site R-40 of the Rupununi Phase. However, the fact that 
this site dates from the middle of the 19th century (table N), more 
than 200 years after the presumed termination of the aboriginal 
period in the Northwest District, suggests that the Koriabo Phase 
sherds may not be associated with the Rupununi Phase occupation. 
Historical accounts and archives relating to the Northwest District 
frequently mention Indians, but the descriptions are too general to 
be tied in with the archeological remains. Although Warrau and 
Carib groups still constitute a large component of the local population, 
there is no way of determining whether they are deculturated descend- 
ants of the prehistoric inhabitants or later immigrants into the area. 
