Personal and Scientific N~ews. t05 
sion of the geographic range of many Unionidse which have 
their best development in the Mississippi basin but also ex- 
tend northeastward to the Laurentian Lake region and the 
Hudson river. Their dispersion is thought to have been fa- 
cilitated by the streams outflowing from the glacial lakes of 
the St. Lawrence basin. 
Geological Survey of Great Britain. We learn that Mr. 
J. R. Dakyns, M. A., who joined the Geological Survey in 
L862, has just retired from the service. Mr. A. Strahan, M. 
A., ha- been promoted to the rank of Geologist on the English 
branch of the Survey, and Mr. C. T. ('lough. M. A., is simi- 
larly promoted on the Scottish branch (in room of the late 
Hugh Miller). The two vacancies on the Stall' of Assistant 
i. sologists are filled by the appointment of Mr. Crosbee Can- 
trill. B. Sc, in England, and of Mr. E. II. Cunningham-Craig 
in Scotland. (Geol. Magazine.) 
Mr. William Libbey, Jr., professor of physical geography 
in Princeton University, expect- to leave Princeton, with a 
part} 7 of six students, for the Hawaiian Islands on June loth, 
the purpose being to study the botany, zoology and geology 
of this group of islands. Collections will be made along all 
of these lines for the Princeton Museum. Some physical work 
will be done in connection with a visit to the crater of 
Kilauea, if possible along the line of the determination of the 
lava temperature and the determination of the spectrum lines 
of the names which accompany the lava outbursts. 
Another Log in a Late Glacial Beach. 
Mr. Ossian Guthrie sends to the American Geologist a 
sample of wood sawn from an oak log recently found in a 
Late Glacial beach of lake Michigan in the north part id' 
Chicago, about fifteen feet above the present lake and nearly 
ten miles distant from the logs noted in our April number 
(page 259). This tree trunk rested on glacial till, and was 
covered along an extent of about forty feet by water-depos- 
ited fine clayey silt, by which it was protected so that its 
wood appears to differ from a modern log chiefly in its consid- 
erably blackened color. Mr. Guthrie announces his intention 
to make two gavels from this wood for the approaching na- 
tional conventions. Its age is estimated as 7,000 years, more 
or less, being the same as the duration of the Postglacial or 
Recent period. 
Geological Map ok Europe 
published inoer tiik auspices of the international congr] s8 
of geologists. 
Dr. Persifor Frazer, who secured the American subscribers 
to this map, writes as follows: -In a recenl communication 
received by me from the 'Geographischer Verlagshandlung' of 
Dietrich Reimer (Hofer and Vohsen, Anhaltstrasse 12, Berlin, 
