A. E. Verrill—The Bermuda Islands; Coral Reefs. 215 
The common form of this species (figs. 72, 72a) in which the 
collines are of moderate height and appear rounded, owing largely 
to the principal septa being wide and pretty regularly rounded 
toward the summit, with nearly even denticulations, may be regarded 
as the typical variety. 
- The most marked variation from the typical form is that in which 
the collines appear sharper or narrower at the crests, or have a gothic 
form, due mainly to the narrowed upper portion of the septa, but in 
part to the greater height of the collines and thinness of the walls. 
Figure 73.—Meandra cerebrum, var. strigosa. Part of a large specimen, 1g nat. 
size. Phot. A, H. V. 
This is the form figured under the name of labyrinthica by Ellis and 
Solander, 1887, and which has generally been known by that name 
in later works. It was admirably illustrated in the plates of Prof. 
L. Agassiz (see our fig. 73), under the name of JV. strigosa, applied 
to it by Pourtalés, who considered it a distinct species.* 
It seems desirable to retain a special varietal name to designate 
this form, and none seems so available as strigosa, which seems to 
be the earliest, except labyrinthica, which cannot be used, because 
it was originally applied to another species (meandrites Linn.). 
* My own description of M. cerebrum in a former article (these Trans., vol. 
xi, pp. 74-76, was based more largely on this variety than on the variety now 
taken as the type form (var. cerebrum), but the figures there given mostly per- 
tain to the latter. Intermediate forms often occur. 
