484 



BULLETIN OF THE BUEEAU OF FISHERIES 



Table 15. — Concenlration of umbo larva: in $00-gallon hourly samples taken at the level of the oyster bed 





50 



40 



^30 



20 





Si 





;o 



/ 2 J 4 5 6 7 a 9 yo // y^ /J 



HOURS 



Figure 31.— Distribution and abundance of the oyster larvfe in relation tothostfigeof the tide 



