||P.401 left column bottom paragraph: "Transmission electron microscopy images show that Synechococcus spp. cells were larger than Cyanobium spp. cells (Fig. 3). Chl [chlorophyll] and volume measurements in Table II confirm this observation. There were also differences in the number and size of carboxysomes in the two strains. Synechococcus spp. have a few large carboxysomes, whereas Cyanobium spp. have many small carboxysomes. A summary of derived carboxysome properties for high- and low-CO2-grown cells of each species is shown in Table III." P.406 right column 2nd paragraph: "The two strains examined in this study had Rubisco active site densities, which were measured on a Chl basis (6 to 14 nmol/mg Chl, Table I), similar to those densities measured previously in Synechococcus spp. At high and low CO2 (Emlyn-Jones et al., 2006, Tables I, III, and IV)." P.407 left column top paragraph: "Rubisco packing densities of 74% (Kepler packing) of the internal carboxysome volume are realistic packing arrangements for both α-carboxysomes and β-carboxysomes based on estimated stoichiometries for both carboxysome types (primary sources Long et al., 2011, Roberts et al., 2012). Based on this arrangement, the concentration of Rubisco active sites within carboxysomes (10.9 mM for both carboxysome types, Table III) is considerably higher than that found in the stroma of C3 plants, where concentrations of 1 to 2 mM are most common (Badger et al., 1984, von Caemmerer and Edmondson 1986)."