Quantity of hemoglobin in the cells
The reference range for hemoglobin Hb content in whole blood is 13 - 17 g/100ml for adult men, and 12 - 16 g/100ml for adult women. 

There are other related metrics : the mean corpuscular hemoglobin concentration MCHC, that is the concentration in a red blood cell (reference range : 31 - 36 g/100mL), and mean corpuscular hemoglobin MCH, which is mass in one cell (reference range : 29 - 35 pg)

So I think that book is refering to different values :  the concentration in the red blood cell itself (MCHC = 34g/100ml), and the resulting concentration in the whole blood (Hb = 15g/100ml).

By the way, there is a value relating Hb and MCHC, the hematocrit Ht, the proportion of volume of whole blood occupied by red blood cells. Reference range 40% - 50% for adult men, 35% - 47% for adult women.