THE - CONCHOLOGISTS’ - EXCHANGE. 25 
«¢ Despatch,” then on special service in the Po- 
tomac. Some time after, information reached 
me that a vacancy would occur upon this ship, 
a vessel made famous by her deep sea sounding, 
under several commanders, and natural history 
researches, under Prof. Alexander Agassiz. 
No time was lost in making the necessary ap- 
plication, and the following day I was gratified 
in receiving the transfer orders. She was then 
at Baltimore, Md., and in the latter part of 784 
did hydrographic work off Gay Head, Martha’s 
Vineyard. A change in commanding officers 
was made in December, and with the new came 
another field of duty, namely, that of testing the 
force and direction of ocean currents at any 
depth. This would be done by an apparatus, a 
current meter, devised by Lieut. J. E. Pillsbury, 
U.S. Navy, her present commanding officer, 
and when in use requires the vessel to be an- 
chored in any depth of water. Many obstacles 
were encountered and overcome, as was fully 
proved by the last anchorage, in 1852 fathoms 
of water, thirty-nine miles off Cape Hatteras; 
and by demonstrating not only the existence, 
but the force and direction of a current, at 200 
fathoms depth. 
As soon as I had grasped the method by 
which we would anchor, the idea immediately 
occurred of putting a dredge on the anchoring 
wire. After some conversation, the command- 
ing officer consented to allow the placing of an 
ordinary boat dredge uponit. The first trial 
took place off Fowey Rocks Light, Fla, and 
much to my disappointment, the net was prac- 
tically empty. It was suggested that, owing to 
the meshes of the net being too large, the quan- 
tity of “mud” so small, and the rapidity with 
which the dredge was drawn through the 
water (about one fathom a second after the 
anchor was tripped) so great, that the contents 
- were washed out long before it reached the sur- 
face. A substitution of an ordinary coffee-sack 
for the net followed. The next anchorage 
yielded about one quart of nicely cleaned resi- 
due, representing at least a dredge full of 
“mud.” Many trials were made to determine 
whether it would be better to fasten the rope 
holding the dredge to the anchoring wire, or 
merely to allow it to run free by means of 
“‘sister-hooks.” It was finally decided to fasten 
it to the wire, about two fathoms from the 
anchor stock. This method has been followed 
during the past two seasons. 
Thus by taking advantage of a golden oppor- 
tunity, I have succeeded in securing forty-one 
dredgings, the greatest depth being 1060 fath- 
oms, in Yucatan Channel, 
The work for the seasons of ’85 and ’86 was 
in the Straits of Florida, between Fowey Rocks 
Light House, Fla., and Gun Cay, Bahamas; it 
yielded twenty-nine dredgings : during ’87, be- 
tween the Tortugas and Havana, Cuba, and be- 
tween Cape San Antonio, Cuba, and Yucatan ; 
yielding twelve dredgings. 
All the specimens collected were submitted 
to Dr. Dall, who kindly named them, retaining 
as remuneration, as many as was desired for the 
Smithsonian Institution. 
The results have exceeded all expectations, 
and, added to those obtained from the surface 
nets and along shore, yield a grand total of 513 
species, running through many families and 
genera. 
The diagnoses of some few species still re- 
main doubtful, but two new ones have been es- 
tablished, a Mitra [first obtained from the 
dredgings of the ‘ Albatross’ ] and a Mathilda ; 
and, one rare Voluta gouldiana, Dall. 
It is hoped during the coming season of ’88, 
to continue the interesting work in the passages 
between the islands of the West Indies, thus 
giving a continuous series of dredgings, from 
Cape Hatteras, to the origin of the gulf stream. 
Sincerely yours, 
WILLIAM H. Rusu, M. D., 
P. A. Surgeon, U. S, Navy, 
PUBLICATIONS RECEIVED. 
West Coast Shells. A familiar description 
of the Marine, Fresh Water and Land Mollusks 
of the United States, found West of the Rocky 
Mountains. By Josiah Keep, A. M., Professor 
of Natural Science, Mills College, Cal. With 
numerous illustrations, by Laura M. Mellen, 
Teacher of Art, Mills College. Presented by 
the author, who has edited in -‘ West Coast 
Shells,’ a book which every student should 
have in his library, simply because of its clear, 
concise diction, the simplicity of its descriptions 
