412 ARCHEOLOGICAL INVESTIGATIONS—II [DTH. ANN, 44 
penetrate to it. When a seepage vein emerges at the foot of a bank 
it cuts away the sand; the clay having its support thus removed, 
falls; and when water from the surface runs over at a place where 
this happens, the clay is carried away and a deep ravine with vertical 
sides cuts back rapidly into the land. As an instance: A farmer, 
desiring to drain a slight depression on his land, cut a narrow, 
shallow ditch, using only a spade, to a ravine. Within two months, 
following several heavy rains, this small ditch was enlarged to a 
ravine 10 to 20 feet deep, 20 to 30 feet wide, cutting back more than 
100 feet from its former outlet. 
The most conspicuous feature of the group is the large inclosure 
marked A on the map (pl. 64), on the farms of Greenhouse, Schaub, 
and Du Pre. It forms an irregular curve, the ends resting on the 
bayou bluff. The south end is shown in Plate 65, a. Its total length 
is almost 3,300 feet; the height ranges from less than 3 to nearly 7 
feet for most of its length; but there is a space of more than 400 feet 
at the northern end where it is almost obliterated by cultivation. The 
breadth increases and extends proportionately. These variations 
raise a question as to whether the work was ever fully completed to 
the extent that it was planned. There are two openings or passage- 
ways toward the south and one toward the west (pl. 64); no doubt 
there was also one toward the north. | South of the west opening is 
an extension on the inner side of the embankment, continuous with 
it, which forms a platform 30 feet across; it appears as if intended 
for the foundation of a building (see pl. 65, 6). 
An outside moat, shown in Plate 66, a, now filled by wash and de- 
cayed vegetation until it is swampy for most of its length, borders the 
outside of the wall for its entire extent. 
On Tassig’s farm, one-third of a mile to the north of inclosure A, 
is another, marked B on the map. It is from 3 to 5 feet high, but 
has been much lowered by erosion; the encircling moat, now 2 to 3 
feet deep, has been partially filled for most of its length, though cut 
much deeper at each end, by the same agency. As constructed, the 
top of the wall was at least 10 feet above the bottom of the ditch 
(pl. 65, ¢). It forms, roughly, nearly one-fourth of a circle, beginning 
at the bluff above Old River and terminating at a large tributary 
ravine. The length at present is 510 feet, but it was once somewhat 
longer, as both ends have been cut off by the caving of the banks. 
There is a gateway to the south and one to the west. The area 
enclosed by the bayou bluff, the edge of the ravine, and the wall, is 
about 4 acres. 
Another inclosure of a different nature lies south of the large in- 
closure, A. From the second gateway here is built up a crooked 
causeway 5 or 6 feet wide at the base and only a few inches higher 
