95 THE - CONCHOLOGISTS’ * EXCHANGE. 
Young Collections. Corner. 
Distribution of Shelis. 
BY -W. W. WESTGATE. 
i read with much pleasure Mr. Simpson’s ar- 
ticle on “ Distribution of Land and Fresh Wa- 
ter Shells in the Tropics.’’ I think shells are 
also distributed by other means. Henry Walter 
Bates, in“ Naturalist on the River Amazon,” 
speaks thus of pumice stone which he found 
floating in the river: “A friend once brought 
me, when I lived at Santarem, a large piece 
which had been found in the middle of the 
stream below Monte Alegre, about goo miles 
farther down the river. Hlaving reached this dis 
tance, pumice stones would be pretty sure of 
being carried out to sea and floated thence with 
the Northwesterly Atlantic current to shores 
many thousand miles distant from the volcanoes 
which ejected them (I have several pieces of 
pumice stone picked on the beach of Galveston 
Island.—W. W. W.) ‘They are sometimes 
stranded on the banks in different parts of the 
river. Reflecting on this circumstance since I 
arrived in England, the probability of these 
porous fragments serving as vehicles for trans- 
portation of seeds of plants, eggs of insects, 
spawns of fresh water fish, and so forth, has 
suggested itself to me. ‘Their rounded. water- 
worn appearance showed that they must have 
been rolled about for a long time in the shal- 
low streams near the sources of the rivers at 
the feet of the volcanoes before they leaped the 
water-falls and embarked on the currents 
which lead directly for the Amazon. ‘They 
may have been originally cast on the land and 
afterwards carried to the river by freshets, in 
which case the eggs and seed of land insects 
and plants (also shells —W. W. W.) might be 
accidentally introduced and safely inclosed with 
particles of earth in their cavities. As the 
speed of the currents in the rainy season has 
been observed to be from three to five mixes an 
hour, they might travel an immence distance 
before the egg or seeds were destroyed.” 
I think man plays an important part in dis- 
tributing shells. Some time ago a fruit dealer 
in this city received a large case of bananas 
direct from South America. When it was 
opened a small boa crawled out. (I now have 
him in alcohol.) S. Jacob, in a little pamphlet 
“The Student’s Aquarium,” speaks of finding 
a “South American copper-head” in the 
‘“ Narrows,”? New York Bay, which he thought 
“had left a fruit vessel at quarantine.” Now, 
if snakes are carried that way, why not shells ? 
Mr. Singley says that “ wild ducks, geese, etc., 
do the distributing.” In ‘‘Conchologia Ces- 
tria’’ several species of Mollusca are spoken of 
as being introduced from England, France, etc., 
viz, Limax flavus, Linn, L. agrestis, Linn, 
L. maximus, FHyalina cellaria, Mull., Actcula 
acicula, Muller. 
I have found a species of Z2#max mm my 
greenhouse, which I thought came from West 
Chester, Pa,, in plants which I had purchased 
there. Several years ago I bought some water 
lihes from Fayette, this State, and planted them 
in tubs, Not long afterwards I got some from 
Florida, now my tubs are filled with PAysa 
gyria, Say, of a different form from those 
found here. 1 do not know whether they came 
from Florida or Fayette County, While I was 
in the drug business T found two small Helices 
in some juniper berries that I was selling. I 
sent one to Professor Dall, and he marked it 
thus: //e/ix, young, like extcetorum, exotic. I 
could give other instances, but [ think this is 
enough tor the present. 
FOREIGN MAILS. 
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ica, West Indies; Steamer Advance, Feb, 18th. 
Bremen, Germany; Steamer Werra, Feb. 18th. 
South and Central America, via Panama; Str. 
Acapulco, Feb, 20th. Hlayti and West Indies; 
Steamer Alvena, leb, 18th. 
Special Cuba mail closes daily, except Sun- 
day, at Philadelphia, rr P. M. 
