Journal op the Mitchell Society. 
46 
\_June 
8. Wind-polished pebbles, and Palaeolithic Man, Collier 
Cobb, of the University of North Carolina. 
The close similarity between pebbles faceted and polished 
by the sand-blast and the implements of early man was indi- 
cated, and the errors which might result from superficial 
observation were pointed out. 
9. Notes on the Zoology of Lake Ellis, C. S. Brimley, 
Raleigh, N. C. 
The paper discusses the occurrence of various insects and 
reptiles taken by the writer and others in the vicinity of Lake 
Ellis, Craven County, N. C., during June, 1905, and May, 
1906. The rare salamander, Stereochilus marginatus, which 
had not been taken for many years, was found to be common, 
and several specimens of the frog, Rana virgatipes, were 
taken. Nine alligators were secured on the two trips by the 
author’s companion, and several rare snakes. Five species 
of dragon fly, new to North Carolina, were secured, and (in 
June, 1905,) numerous specimens of the yellow fly (Diach- 
lorus ferrugatus). Notes on other members of the Tabani- 
dae are also given. 
10. Single Phase Railway Work, J. E. Latta, of the Uni- 
versity of North Carolina. 
11. The Relation of the Cattle-tick to Southern Agriculture, 
Dr. Tait Butler, State Veterinarian, Raleigh, N. C. 
12. The Design of High Masonry Dams, William Cain, of 
the University of North Carolina. 
The method of finding the resultant of the water pressure 
and the weight of masonry pertaining to any horizontal joint 
of a dam is given; also the decomposition of the vertical com- 
ponent of this resultant along the joint according to the 
usual hypothesis. The hypothesis of the conservation of 
plane sections, in the case of a battered wall, is then criti- 
cised and the resulting vertical unit pressure at a face of the 
