658 
points on the line, terminating at Senegal. A blind 
Fusus was dredged in over twenty-five hundred 
fathoms. These instances are sufficient to show the 
extension of arctic forms into tropical regions, but 
with these are found a great number of mollusks yet 
unknown in the North Atlantic. The abyssal fauna 
of the African coasts is therefore not composed soiely 
of arctic immigrants. Lovén has shown that the 
arctic species range at greater depths as they advance 
southward, —a fact confirmed by other naturalists, 
and by the researches of the Talisman party. It is 
probable, therefore, that the idea now generally en- 
tertained by malacologists is correct, that the range of 
SCIENCE. 
[Vou. III, No. 69, 
able forms first signalized by the U. S. fish-commission 
from deep water in the North Atlantic, among which 
may be mentioned Pholadomya arata, Mytilimeria 
flexuosa, etc. W. H. DALL. 
THE RELATION OF THE MOUND-BUILD- 
ERS TO THE HISTORIC INDIANS: 
In Kosmos, vol. xiv., parts ii. and iii., will be found 
two papers, by Dr. Emil Schmidt, on the relation of 
the mound-builders to the modern Indians. The 
reputation of the author as a student of American 
DEEP-SEA MOLLUSKS LIVING AT A DEPTH OF FROM 1,500 To 2,500 METRES. (Taken from La Nature.) 
Calliostoma, Modiola, Fusus, Dentalium, Turbo, and Terebratula are represented. 
these animals is determined by temperature rather 
than by the intensity of light or other factors. The 
investigations of the Talisman have considerably en- 
larged the number of Atlantic stations for mollusks 
reputed peculiar to the Mediterranean. Among these 
are Cassidaria tyrrhena, Umbrella mediterranea, Xe- 
nophora mediterranea, Carinaria mediterranea, Pyra- 
midella minuscula, Pecten pes-felis, Spondylus Gus- 
soni, and a number of others. Dr. Fischer concludes 
that the Mediterranean has very few peculiar species, 
and appears to have been populated in great part by 
colonists from the Atlantic, after the geological period 
in which communication with the Indian Ocean was 
cut off. 
Lastly, the expedition obtained some of the remark- 
aboriginal history will give to these papers great 
weight in Germany. It is important, therefore, in 
the interests of true science, to know what they con- 
tain, to indorse them where they are in harmony 
with the latest investigations, and to correct any 
mistakes into which the author may have fallen. 
After paying a just compliment to the Peabody mu- 
seum, the Smithsonian institution, and the Bureau 
of ethnology, and expressing his regret that the laity 
are still disposed to behold something wonderful and 
mystical in every thing that the mounds reveal, Dr. 
Schmidt passes in review the history of mound ex- 
ploration for the last century. Capt. Hearne, in 1791, 
expressed the opinion that the earth-works could 
not have been the production of hunting Indians, 
