Edible Mollusca of the Oregon Coast 195 
ity. On March 29th, 1919, however, both male and female clams 
were in a spent condition. There is probably some variation in 
the duration of the spawning season from year to year and, no 
doubt, a like variation under different conditions. My observa- 
tions were made at Newport, Oregon, where the clams were 
taken from the protected tide flats of the Yaquina River. 
The examination of males on July 31st did not reveal the 
presence of formed spermatozoa. It is quite clear that there is 
no summer spawning of this species on the Oregon coast. In 
September 1918, small clams about 50 mm. in length were quite 
abundant in the gravel beds of Netarts Bay. Although the rate 
of growth of Schizothaerus nuttalli has not been determined, it is 
very probable that these small clams may have resulted from the 
spawn of the previous spring. 
3. Paphia staminea (Conrad). 
There is some evidence to believe that the “‘little neck clam” 
has both a spring and a late summer spawning season on the 
Oregon coast. Examinations made at Newport on March 30th 
revealed ova and spermatozoa apparently in a state of maturity, 
the latter very active (Figure V, 7, 8, 9). The condition of the 
bodies of both males and females indicated that the spawning 
period was approaching. On September 22nd of the same year 
the species was examined at Coos Bay and found to be in a con- 
dition identical with that observed at Newport in March. The 
ova were to all appearances fully matured and the spermatozoa 
were very active. 
On July 31st, 1918, well formed spermatozoa were found in 
this species at Netarts Bay but they were in a resting condition. 
I have not examined the species at Newport in September or at 
Coos Bay in March. In both localities, however, the clams were 
taken within protected bays and the variance in temperature of 
the two places cannot be great. It would appear, therefore, from 
our present incomplete knowledge, that Paphya staminea may 
spawn in both the spring and late summer seasons on this coast. 
4. Mya arenaria Linnaeus. 
The reproductive organs of this clam have been examined 
[19 ] 
