PREHISTORIC SETTLEMENT AT LATTON LANDS 127 
Methodology and results 
One kilogram of sediment was floated in water on to 
0.5 mm mesh and the flots dried. Residues were also 
sieved to 0.5 mm and dried. Flots were scanned 
under a binocular microscope at magnifications of 
x10 and x20. Residues were also checked for shells, 
although the flotation was generally found to have 
given adequate shell recovery. The abundance of taxa 
was recorded on a scale of + (present, 1-2 
individuals), + + (some, 3-10 individuals) and +++ 
(many, 11+ individuals). An estimate was also made 
of the total number of individuals in each flot 
excluding Cecilioides acicula. This species was 
excluded because it burrows deeply and provides no 
useful information on conditions as a sediment or 
soil formed. C. acicula can be extremely numerous 
and its inclusion in the total tends to obscure the 
results from the other species. The results are 
presented in Table 3. Nomenclature follows (Kerney 
and Cameron 1979). Overall the preservation and 
species diversity was moderate to poor. 
Identification to species level proved difficult with 
Lymnaea sp and Vallonia sp. due to the fragmentary 
nature of the shells (See Figure 3 for the location of 
the samples). 
Interpretation 
Ditch terminus 366: The two lowermost samples 
<17> and <18>, of the tertiary fill (397) were 
dominated by freshwater species Anisus leucostoma 
and to a lesser extent Lymnaea sp. The identification 
of Lymnaea was difficult since the shells were fragile 
with only a few examples of the tips of the apices 
surviving. Terrestrial molluscs were present, albeit in 
very low numbers. A.Leucostoma is considered to be a 
slum species, tolerant of poor water conditions, 
inhabiting ponds and ditches subject to drying or 
stagnation. Of the terrestrial molluscs, Cochlicopa 
sp., Cepaea sp. and Trichia hispida fall into the 
intermediate group, none of which are particularly 
diagnostic of either shaded or open habitats. The 
presence, however, of Vallonia sp. may suggest open 
ground/grassland nearby. In addition, although 
Carychium tridentatum is classed as a shade-loving 
species, it also commonly inhabits the base of the 
leaves of grasses in ungrazed grassland. 
Assemblages from the upper tertiary (397)/ 
<19>, and secondary fill (368)/<20>, show a 
decrease in the number of freshwater molluscs 
suggesting silting and drying of the ditch. The 
addition of Oxychilis cellarius and Aegopinella nitidula 
may suggest a slightly more shaded environment, 
although this may be local to the vegetation around 
the ditch. 
Molluscan preservation was very low in ditch 
terminus 383. The assemblage from fill (381)/<6> 
contained a few freshwater molluscs; cf. Lymnaea sp. 
suggesting wet conditions. There was, however, a 
Table 3. Molluscs 
