MADREPORA. 201 
Verrill states that this form is quite distinct from . surculosa, and proposed to give it 
the rank of a species. Until the type specimens have been compared and the differences 
noted, I think it undesirable to change the arrangement proposed by Dana. 
Tahiti. 
Var. diffusa, Dana, Zoophytes, p. 446. 
Branchlets proliferous above and similar in size and form (? to those of the type), but the 
branches are 4 to 2 in. thick, distantly coalescent, with very large spaces ; the branchlets are 
more remote, often 1 in. apart. The type specimen is in the possession of the Boston 
Society of Natural History, and consists approximately of one-fourth of the whole colony ; it 
is 18 in. long and 15 in, broad. (Dana.) 
Dana remarks that this variety has more the habit of M. sudulata than of M. surculosa, 
but that it differs from that species in the length and character of its branchlets. 
