470 NOTES ON THE TEN THOUSAND ISLANDS, FLORIDA. 
the beak turns to the left of the user, and probably was selected by a left-handed 
individual. 
In Fig. 26 is shown a shell (Codakza orbicularis) which has been an imple- 
Fic. 26.—Shell implement. Chokoloskee Key. 
(About full size.) 
ment of some sort. This shell was dug 
by us from one of the great ash-heaps 
on Chokoloskee Key, which there and 
on certain other keys seem to be the 
remains of fires long continued. 
Spread over the shell keys are con- 
siderable numbers of shells (Arca pon- 
derosa) many with a hole below the 
hinge, as shown in Fig. 27. 
Cushing (p. 88) speaks of nets 
having ‘“‘sinkers made from thick, 
roughly perforated umboidal bivalves, 
tied together in bunches,’ no doubt 
referring to the Arca ponderosa shell. 
The number of these shells having 
holes, when found on the shell keys, 
greatly preponderates over those that 
do not have a perforation, in which they greatly differ from the сопеһв and other 
large shells found on the keys. Тһе reason for this is plain. 
were selected for food primarily, and the shells of only some 
of them were subsequently used as tools. Тһе Arca, on the 
other hand, is small and moreover is found in compara- 
tively deep water when alive. Presumably conditions were 
such that the Arca was not sought as food and the supply 
of shells needed for tools came from the beaches. Іп this 
event a very large proportion of the shells carried to the 
keys would be perforated for use. 
Many of the Arca ponderosa shells in our possession 
The larger shell-fish 
Fic. 27.—Perforated Arca shell. 
Little Marco. (Length 2.15 
inches.) 
show decided wear on the edges, which leads us to believe they were used as dimin- 
utive scrapers. Probably Arca shells were employed for different purposes—for 
tools as well as for net-sinkers. 
