106 THE NAUTILUS. 
apparently most unfavorable to the propagation of the species, which 
is entirely isolated as far as yet observed. The entire island was 
submerged for about ten hours to an average depth of about two 
feet during the hurricane of August 27, 1893, and almost all vege- 
tation was killed at that time, a circumstance which leads to the 
opinion that the species is of very recent introduction. The terres- 
trial species of mollusea so far observed on the island are: 
Polygyra espiloca Rav. Pupa fallax Say. 
Triodopsis hopetonensis Shutt. Pupa pentodon Say. 
Cochlicella ventricosa Drap. Succinea campestris Say. 
Vertigo rugosula Sterki. Succinea inflata Lea ? 
I have a single dead specimen of Mesodon thyroides Say, most 
likely washed from the neighboring mainland, and a few specimens 
of Stenogyra decollata L., certainly brought from Charleston, where 
it is abundant. 
ISAAC LEA DEPARTMENT. 
[Conducted in the interest of the Isaac Lea Conchological Chapter of the Agassiz Associa- 
tion by its General Secretary, Mrs. M. Burton Williamson. ] 
UNIOS. 
{Excerpts from the Report of Dr. W. S. Strode. From the Transactions of the 
Isaac Lea Conchological Chapter for 1895.] 
* To the Spoon River, only three miles away, two or 
three hurried visits have been made. With one exception only the 
usual shells of this stream were found. I was fortunate in striking 
a new bed of Unios. It was ina little bayou six feet wide and 
about three deep by twenty long, just above a rough ledge of lime 
and sand rock. The environment was suitable to many species, and 
the mud and sand at the bottom of this little cove was literally 
packed with them. In half an hour I had thrown out on the clean, 
white sand several bushels of various species, as Unio tuberculatus, 
anodontoides, plicatus, rectus, ligamentinus, luteolus, occidens, gibbo- 
sus, laerymosus, pustulosus, trigonus, alatus, gracilis, ebenus, levissi- 
mus, complanatus, rugosa, donaciformis, and several of the gigantic 
multiplicatus peculiar to this stream. Some of these species had 
been so long in this still water, and were so hoary with age that 
they were moss grown. When I had thrown out about all the little 
bayou contained, I selected the finer specimens of such species as I 
