Archaeological Investigations in Jefferson County, Mo. 207 
The Middle Mississippi Phase is represented at the Boyce 
mound and village, the McCormack cemetery, the Jenni mound 
and the Herrell mound and village. Middle Mississippi traits 
are several characteristic pottery shapes, two pottery wares, 
limited use of projectile points, awl sharpeners and houses with 
rectangular floor outlines. 
There are indications that the Boyce mound and village 
and the McCormack cemetery belong to one aspect and the Her- 
rell mound and village belong to a second distinct aspect. How- 
ever, it is necessary to conduct more investigations before we can 
clearly define them. For the present we will define the former 
as belonging to the Plattin focus and the latter as belonging 
to the Kimmswick focus. Surface examinations of several 
sites indicate that there are several locations containing the 
Plattin focus and several locations containing the Kimmswick 
focus from this and surrounding counties. 
The Plattin focus has the following characteristic deter- 
minants (other than Pattern or Phase determinants) : stone box 
gtaves without rock covers containing single extended burials 
with grave furniture near an area containing pottery apparently 
left as a part of a ceremony carried out in conjunction with the 
funeral rite. Burials are in cemeteries adjacent to but not in 
the villages. There are three types of rectangular houses. 
Small rectangular houses were made with slightly depressed 
floors next to large rectangular houses with walls having post 
Supports which were set in ditches and houses made by placing 
poles with chisel shaped bottoms on the habitation surface to 
support wattlework. Roofs were of thatch. Fireplaces were 
two or three small bowl shaped clay pits next to each other 
and also outside the houses. Ceremonial pottery from the mounds 
and the burials is Imperial Plain ware consisting of small 
olla or jar forms with loop handles, some water bottle pots 
and some plates. The utilitarian ware found mainly in the 
village is of Plattin Clay Tempered and is in the form of 
common bowls and large jar forms usually with angular shoulders. 
