A. E. Verrill—The Bermuda Islands; Coral Reefs. 217 
but sometimes long and parallel in some parts. In nature, however, 
it occurs of various irregular forms, often merely forming thick crusts 
when young, as in other related forms. When well grown it usually 
can be readily distinguished by the open or cellular appearing, rather 
deep and wide calicinal grooves, which have sloping sides and are 
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Figure 74.—Mceandrina sinuosa Lesueur, showing his varieties; a, b, var. 
limosa, polyps partly retracted; c, d, var. viridis; ce, profile of collines, 
enlarged; d, polyp of terminal calicle, much enlarged. Photographed from 
Lesueur’s figures. 
Figure 74a.—The same; a, var. rubra; b, var. vineola, both much enlarged. 
Photographed from Lesueur’s figures. 
Figure 74b.—Meceandra clivosa, terminal part otf a calicinal valley with the 
polyps partially expanded, much enlarged. Photographed from L. Agassiz. 
therefore wider above, and by the gothic form of the larger septa 
and rather narrow acute collines, with thin, simple walls. The full 
grown calicinal grooves are usually 8 to 10™™ deep, and 9 to 13™™ 
wide, from crest to crest of the collines. 
The principal septa are thin at base with a distinct, roughly 
spinulose paliform lobe; they decrease in width distally, either regu- 
