present in varying intensities from early May through June with a high point 

 of 230 per 35 gallons during the week of June 8. With the exception of one 

 small concentration of larvae around the first part of October,, the spawning 

 season was over by the end of June. 



Venus larvae. — Figure 8 and table 3 depict abundance data for Venus 

 larvae in Wickford Harbor for 1952. Larvae first appeared during the week 

 of May 18, when the surface temperature was about 13° C, and reached a 

 maximum of 5,h00 straight-hinge larvae per 35 gallons the week of June 15. 

 Late umbone stage larvae appeared for the first time around June 23 and were 

 present consistently in the samples through the middle of July. The peak of 

 abundance occurred during the week of July 13, when the weekly average was 

 219 mature larvae per 35 gallons. Although there was a small count of late 

 umbone stage larvae the latter part of July, spawning for all practical pur- 

 poses appeared to be over by mid-July. 



Greenwich Bay, 195l 



Figures 9 and 10 and table h show the abundance of Venus larvae at 

 two stations in Greenwich Bay. Figure 9 is a composite of two stations in 

 the western half of the bay, and figure 10 is a similar composite of two 

 stations in the eastern half. Samples were taken twice a week during the 

 spawning season. Bottom water temperatures in Greenwich Bay during 195l 

 are shown in table 1 and figure 11. 



Sampling began May U, and the first young larvae appeared the week of 

 May 20 in the western half of the bay, when the bottom water temperature 

 was between 15° and 16° C. The first late umbone stage larvae appeared 

 during the week of June 10 in the eastern half,, and they occurred sporad- 

 ically in the samples throughout the summer. The greatest weekly average 

 of young larvae was 1,500 per 35 gallons from the eastern half of the bay, 

 and the largest weekly average of late umbone stage larvae was 70 per 35 

 gallons in both sections of the bay. The last sample containing Ven us 

 larvae of any kind was taken October 12. 



Greenwich Bay, 1952 



Figures 12 and 13 record the abundance of Venus in the eastern half 

 and in the western half of Greenwich Bay during 1952. A semi -weekly schedule 

 was maintained throughout the spawning season, Bottom temperatures in 

 Greenwich Bay for 1952 are shown in table 1 and figure 11. 



Sampling began on May 20, and the first larvae appeared during the 

 week of May 25 in both parts of the bay, when the bottom water temperature 

 was probably between 16° and 17° C. Spawning continued at varying intensi- 

 ties for the remainder of the summer, finally ceasing by the end of Septem- 

 ber. Much of the time, the spawning intensity was low, Seldom did the 



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