Edible Mollusca of the Oregon Coast 197 
Mya arenaria in the Siuslaw River which in 1919 had become 
depleted. Judging from the experience of the past few years, the 
most suitable time for artificial culture in this locality is in 
November or early December, if high water does not prevent, 
when large numbers of small clams from 10 to 25 mm. in length 
are to be found near the surface of the mud under patches of eel 
grass. These should be replanted in depleted areas, the thinning 
out process permitting them to mature more rapidly than would 
be possible in the aggregated groups in which they are naturally 
found. The planting may be accomplished very rapidly by the 
use of a sharp pointed stick for making shallow holes in the mud 
into which the young clams are dropped siphon end up. 
5. Cardium corbis Martyn. 
The “cockle” is the only hermaphroditic clam coming under 
the observation of the writer on the Oregon coast. During the 
late fall and winter months it is rarely possible to distinguish the 
ova or spermatozoa in this species. The sex elements begin to 
appear in the spring, the spermatozoa being observed as early as 
March 29th at Newport, Yaquina Bay. Development of ova and 
spermatozoa continues through the summer, spawning apparently 
occurring from about the middle to the latter part of September. 
On September 22nd ova appeared to be mature and the sperma- 
tozoa were in a state of great activity. From October to March 
the reproductive organs pass through phases of reorganization, the 
oocytes and spermatocytes becoming differentiated in the early 
spring. Histological sections through the reproductive organs 
clearly show the spermaries massed about the ovaries (Figure V, 
He 14). 
6. Pholadidea penita (Conrad ). 
An examination of the spermaries of males of this species 
on March 27th at Nye Beach revealed all stages of development, 
in the same individual, from early spermatocytes to fully devel- 
oped spermatozoa. No activity of the latter, however, could be 
detected. On August 19th observations in the same locality indi- 
cated large, well developed ova and apparently mature spermato- 
[ 21 ] 
