280 THE ESSEX NATURALIST.
Peat. Shell-bed.
N.E. Ena montana ..(Drap.) .. .. .. .. — 2
., obscura (Mull.) .. .. .. .. .. — 7
Clausilia rugosa (Drap.) .. .. .. .. — 63
E. „ rolphii Turton .. .. .. .. — 3
Balea perversa (Linne).. .. .. .. .. — 3
Marpessa laminaia (Mont.) .. .. .. .. — 28
Cecilioides acicula (Mull.) .. .. .. .. — 1
Punctum pygmaeum (Drap.) .. .. .. .. 4 198
Gonyodiscus rotundatus (Mull.) .. .. .. 4 673
E. „ ruderatus (Hart.) .. .. .. — 2
Vitrea crystallina (Mull) ........ 2 440
Retinella nitidula (Drap.) .. .. .. .. 5 182
pura (Alder).......... 2 97
radiatula (Alder) ........ 1 121
Oxychilus ceilarium (Milii.) .... . . . . 7 25
Zonitoides nitidus (Mull.) .. .. .. .. — 15
Arion sp. ............ 396 1739
Limax sp. .. . . .. .. .. .. 1 126
Agriolimax laevis (Mull.) .. .... .. — 54
Petasina fulva (Mull.).......... — 45
Trochulus lihertus (West.) ........ 2 50
striolatus (C. Pfr.)........ — 13
Vortex lapicida (Linne) .. .. .. .. — 11
Arianta arbustorum (Linne) .. .. .. .. 1 21
Helix nemoralis (Linne) . . .. .. . . 3 347
., hortensis (MOM.) .. .. .. .. — 3
Pisidium personatum Malm .. . . .. . . — 149 valves
cinereum Ald... .. .. .. 4 valves 93
Ova of Helicoids .......... 30 70
E . . Not known living from N. Essex.
N . . Not hitherto recorded from N. Essex as fossil.
G. ruderatus is not known living in these islands.
V. concinna is not known living; all are from the peat and marl.
P. elegans is certainly extinct in the neighbourhood and is only known living
from two or three spots in the neighbourhood of Pleshey.
The subterranean species, C. acicula, is probably not fossil. The single
example has a very fresh appearance and it is quite out of place in a marl.
Several species of slugs are comprised in Limax sp., but one cannot name
these degenerate internal shells with precision. Two species, P. elegans and
S. putris, only occurred at the extreme limit of the deposit. The former is not a
marsh form. As to the conditions indicated there is no evidence of a stream or
flood debris and the few freshwater forms probably lived in small puddles. It is
clearly a swamp deposit, the shells lived where found audits deposition must cover
a fair amount of time. There must have been a heavy rainfall and warmer
summers and winters. There is no local evidence as to its place in the Holocene
scale, but, judging from similar deposits in other parts of England these conditions
had long ceased before the Early Bronze Period. One can only say it is Early
Holocene. A similar story is told in other parts of Essex as at Copford, Chignal
St. James, Felsted, Harwich, Roxwell and Shalford, and the probability is that
there are many still undetected.