554 U. S. BUREAU OF FISHERIES é 
7. The crates can be planted on barren mud flats, and sand bottoms 
or directly over the spawning beds, thereby obtaining the maximum 
use of the limited inshore areas. 
8. This type of crate can be used successfully, except in a few 
regions where the tidal currents are unusually strong. 
OYSTER DRILL 
At the request of the oyster companies operating in Chesapeake 
Bay, near Norfolk, Va., the bureau, since last October, has under- 
taken a systematic investigation of the oyster drill, with the view 
to discovering a method of checking the destruction of oyster beds 
by this pest. Dr. Henry Federighi, who is conducting this investi- 
gation, has established a laboratory (through the courtesy of the 
United States Public Health Service) at Craney Island, Norfolk, 
Va. The program of observations consists of a study of distribu- 
tion, migration, propagation, and behavior of the organism. Field 
observations made during November and December show that at 
low winter temperature the drili becomes inactive. Further dis- 
cussion of these studies may be found on page 658. 
CLAMS OF THE PACIFIC COAST 
During 1926 investigation of the clams of the Pacific coast was 
continued by H. C. McMillin, scientific assistant, and Prof. F. W. 
Weymouth, of Stanford University. Field work was carried on by 
Mr. McMillin from April to September. An examination of the 
commercial catch on the Washington beds indicated serious deple- 
tion. The beds at Massett, British Columbia, were examined and 
shells collected for growth study. Spawning was observed at Cor- 
dova, and the set of young (1-year-old) on various portions of the 
bed was determined. Swickshak Beach showed the heaviest set of 
any Alaskan bed. Data were collected here to determine the correct 
status of the form now described as Stligua patula var. alta. 
Shells were collected at new places, and material is now available 
for a study of growth on all important beds. A number of shells 
from animals of known sexes were measured, and norms of growth 
were constructed for each sex. Although the sexes are separate in 
this species, there is no significant difference between them when 
pene and determinations made without reference to sex give valid 
results. 
Razor clams move freely through the sand in a vertical direction. 
Observations indicate that they are closely confined to a limited area 
and do not migrate. Only part of them feed at one time and are 
in position to be taken by the diggers; the others remain inactive at 
some distance below the surface. The commercial digger covers the 
ground on successive days without apparent reduction in catch. It 
is difficult, therefore, to determine the abundance on any one bed. 
Depletion may show in the commercial catch, but a definite measure 
of the actual state of the resource can not be made. By marking 
the beach with permanent stakes, the same area can be dug each day © 
and the catch recorded. A limited numbere of such observations 
indicate that beds that have been subject to heavy commercial dig- 
ging will show a rapidly decreasing daily production. 
The razor-clam beds of Washington are in urgent need of protec- 
tion. Tourist and commercial digging have so reduced the popula- 
