218 A. EF. Verrill—The Bermuda Islands; Coral Reefs. 
larly or in a gothic form, and are quite narrow at the apex, which 
projects a little above the wall and bears a few rough denticles; the 
inner edge is covered with rather irregular, rough, often spinulose 
or lacerate divergent or ascending denticles; their sides are sharply 
and roughly granulose or spinulose. Very narrow and thin secon- 
dary septa, disappearing below, usually alternate with the larger 
ones, but are often absent, which results in wide, open interseptal 
spaces. When they are present there are about 22 to 24 septa toa 
centimeter. Those on opposite sides of the collines usually alternate, 
and the thin crest of the wall is often a little zigzag. The wall 
becomes thicker below and solid. 
Dr. Vaughan gave some excellent photographic illustrations of 
this variety, some of which are considerably enlarged (op. cit., 1902, 
pls. ix-xiii), but the name viridis, used by him, did not originally 
apply to this form, for it was given to a color variety of J. stnwosa 
Les. (see our fig. 74, ¢, d, copied from Lesueur), which is a very 
different coral, with much lower collines, rounded at the top, and 
very narrow calicinal grooves, which, according to Lesueur’s natural- 
size figure, made to show their arrangement (his pl. 15, fig. 5a) 
measure only 4 to 5™” from crest to crest of the walls and 4.5 to 5™™ 
from the polyp mouths of one series to those in the next. These 
dimensions are scarcely half as large as in the coral under discussion 
here. Indeed, the dimensions given and the low collines, as figared 
by Lesueur in his profile views, not only of the var. viridis, but of 
all his other varieties of MW. sinwosa, can scarcely apply to any West 
Indian species except M. clivosa.* ‘That is the only meandriniform 
coral of this fauna that has such small collines and narrow grooves. 
* After a careful study of this matter I believe that his sinwosa and all its 
color varieties, figured by Lesueur, should be referred to M. elivosa (Ellis and 
Sol.), which is the only American species having such low and narrow collines 
as he figures. 
Moreover, the figures of the polyps which he gives, and which I have repro- 
duced here, of four of his varieties, agree best with those of M. clivosa, as 
figured by L. Agassiz (see our fig. 74b). M. clivosa is also one of the most abun- 
dant species at St. Thomas, in shallow water, where Lesueur obtained his speci- 
mens, gathering them by hand, as he stated, while wading on the reefs and 
without any special appliances. In fact, it would be far more likely to be 
obtained in that way than either of the other species, which are more massive 
and grow in deeper water. Moreover, so far as known to me, M. clivosa is the 
only species which has such various and bright colors as Lesueur described. 
His varieties are described as scarcely differing at all, except in colors. 
At any rate, there can be no direct relation between var, viridis and our var. 
strigosa of M. cerebrum, for they stand almost at the opposite extremes of the 
various forms of the mzandriniform corals of this region. 
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