at 
1903.} HAUPT—DEEPER NAVIGABLE CHANNELS. 199 
be placed in the same genus with G.? or/manni. In sculpture it 
suggests the carinated forms that White has very doubtfully referred 
to Lioplax endlichi from the Bear River formation. 
Locality.—W ettacombe’s ranch, near Musselshell River, in the 
vicinity of Harlowton, Montana. 
Horizon.—Upper part of Lower Cretaceous or base of Upper 
Cretaceous. 
° 
EXPLANATION OF PLATE. 
Unio farrit Stanton. 
Fig. 1. Right valve of type. 
Fig. 2. Right valve of compressed form, probably male. 
Unio douglasst Stanton. 
Fig. 3. Left valve of a small specimen. 
Fig. 4. Dorsal view of an average-sized specimen. 
Viviparus montanaensis Stanton. 
Fig. 5. Aperture view of the type, enlarged. 
Goniobasis ? silberlingi Stanton. 
Fig. 6. Aperture view of the type, enlarged. 
Goniobasis ? ortmanni Stanton. 
Fig. 7. Aperture view of fragmentary specimen with strong sculpture, 
enlarged. Outer lip restored from another specimen. 
Fig. 8. Dorsal view of a similar specimen, enlarged. 
Fig. 9. A specimen with only two spiral lines on the spire, enlarged. 
Fig. 10. Aperture view of a specimen without spiral sculpture except on 
back of last whorl, enlarged. 
Campeloma harlowtonensis Stanton. 
Fig. 11. Aperture view of the type. 
Fig. 12. Similar view of a broader, more umbilicated specimen. 
REACTION AS AN EFFICIENT AGENT IN PROCURING 
DEEPER NAVIGABLE CHANNELS IN THE IMPROVE- 
MENT OF RIVERS AND HARBORS. 
BY LEWIS M. HAUPT, A.M., C.E. 
(Read April 2, 1903.) 
Consumption, production and distribution are the three main 
elements of trade. Without great facilities for distribution it is 
not possible to maintain a nice adjustment between supply and 
demand. One section of the earth may be starving, while another 
may be burning its excess of food for lack of cheap transportation. 
PROC. AMER. PHILOS. SOC. XLII. 173. N. PRINTED AUG. 5, 1903, 
