336 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
and estuaries. The character and volume of these ancient streams must have tem- 
pered the sea water and produced the most thrifty conditions for the living of the 
oyster. In the Pliocene (Miocene?) we here find the fossil shells of myriads of oysters 
that were decidedly of a brackish- water type, small, single, and thin-shelled, reminding 
one of the Blue Points of Great South Bay. The shells are rounded, regular in shape 
and perfect in outline, attesting the peaceful conditions of their ancient life. They 
show no trace of clustered living. 
The natural causes that afterwards destroyed the prosperity of a molluscan age 
are yet to be ascertained. Certain it is that the incurrent streams were sufficient in 
force and volume to gully out valley and moor, and to roll seaward from far-distant 
places the huge fragments of mire-loving animals. It is not until we examine the 
deep layers of soft, black, river ooze, forming to-day above the phosphate, that we 
find the first oysters of a raccoon-like type. In the deepest ooze-layers the remains of 
clustered oysters are few and fragmentary, suggestive of age, transportation, and hard 
usage. Nearer the shore, and in shallower mud-banks, oysters of all gradations of 
bunching characters may be found everywhere. 
There seems abundant evidence for regarding the living oysters of the State as 
the survivors of an ostreous golden age, survivors that have struggled successfully 
against changed and adverse conditions of living. They have become inured to 
extreme saltness of water, almost that of the sea; they have learned to avoid the 
submerging mud by growing in clustering masses and by casting anchor along the 
firm shore-line, often having to build the very land on which to survive. They have 
learned to Jive their life as much in air as in water, and in their out-of- water position 
to endure the cold of winter and the scorching heat of the sun. Even under these 
hard conditions the oyster’s struggle for existence is still an uncertain one. Huge 
shell banks, miles in length, often 10 feet in height, have been in time formed of rac- 
coon clusters, whose anchorage along the muddy margins has been unstable. A tide 
unusually strong will roll up and scatter high along the dry beach many bunches of 
living shells. These are often seen, weeks perhaps out of water, still guarding jeal- 
ously the few remaining drops of life-giving moisture. 
The appearance and formation of raccoon beds may be understood most clearly 
by referring to the accompanying illustrations of typical natural beds, selected from 
a series of photographs taken by the writer during the cruise. They represent an 
oyster ledge (Plate lxii), an oyster flat (Plate lxiii), and an oyster island (Plate 
lxiy). Plate lxy marks the tidal zone of oyster life, indicated everywhere at lowest 
tide upon stakes and piling. Plate lxvi shows an extended raccoon-bearing locality. 
The oyster ledge* (Plate lxii) is seen from the shore side. The dark-colored shore 
strip exposed by the receding water shows the limits of high and low tides. In this 
zone will be seen the living raccoon clusters anchored in the soft mud, some in mas- 
sive colonies, appearing velvet-like, as in the left of the plate, others scattering, as in 
the right, anchored less firmly in the soft ooze. The white beach composed of dead 
shells has for its lower margin the line of high water, a line that is well marked in 
the picture; this beach, literally a shell heap, rises gently to a firm crest 10 feet 
above high tide. The size of the shell heap points to its antiquity; many shells are 
Stono River, east shore, 3 miles from mouth, March 6, 1891. 
