Zoology and Botany. 69 
perience every day shows the errors of critics in this respect. 
Certainly few authors have had more extensiv 
experience in writing strictly scientific books for the public than 
“Tabulata.” Why, then, should this important class of corals be 
omitted from such a work? As for the Actinia, their relationship 
enough even to form beds of li : 
stances. It forms solid coral-like masses, two or three inches in 
diameter. Some coral-reef species grow even larger. And ‘in 
Paleozoic times, the Bryozoa were relatively of still greater 1m- 
portance, some of the so-called “ true-corals,” evidently belonging 
to this group, in addition to those generally referred to it. e 
stony Algw, also, are not to be ignored in treating of coral-reefs, 
and the half page devoted to them, might well have been extend- 
rather than omitted. Darwin i 
mestones, composed almost entirely of their remains, may be 
Seen In many American museums. 3 ; 
Mr. Dunean, in criticising Dana for adopting the classification 
that he prefers, makes this remark; “The introduction of Ameri- 
