A. E. Verrill—The Bermuda Islands; Coral Reefs. 213 
nearly the whole breadth of the valleys, and the tissues become much 
more translucent. In contraction the column-walls of the polyps 
fold inward and downward over the septa, while the disk contracts 
to the breadth of the floor of the valleys, the tentacles having their 
bases over the groove outside the paliform lobes, as in fig. 71e. 
The tentacles of the living polyps (fig. 71le) are not very long, 
rather slender, tapered, knobbed or obtuse at tips, alternately larger 
and smaller; the outer ones are the smaller, more erect, and have 
whiter tips. Mouths small, oblong or elliptical, with a whitish bor- 
der. Disk deep yellow with faint white radiating lines. Ccenen- 
\chyma and polyp columns lemon-yellow to orange-yellow, sometimes 
dark ocher-yellow. In partial or complete contraction the septa and 
coste show through as whitish radial lines. 
It is common on the inner as well as on the outer reefs. On the 
reefs in Castle Harbor it is abundant, but seldom grows to great size 
there. It apparently does not occur in Harrington Sound. It is 
also common on the Florida reefs and keys, and throughout the 
West Indies. 
Meeandra cerebrum (Ellis and Sol.). Brain Coral. Figs. 72-72b; 73, 73a (6-9). 
Madrepora cerebrum Ellis and Solander, Hist. Zooph., p. 163, 1786. 
Meandrina sinuosa Verrill, Bull. Mus. Comp. Zool., i, p. 49, 1864 (non Mean- 
drina sinuosa Les., Mem. Mus. Hist. Nat., vi, p. 278, pl. xv, figs. 4-9, 1820 ; 
with varieties viridis, rubra, vineola, limosa, appressa, most of which evi- 
dently belong to clivosa. 
Meeandrina labyrinthica, M. labyrinthiformis, and M. sinuosissima of many 
writers. 
Meandra cerebrum Verrill, these Trans., xi, p. 74, plate x, fig. 4; pl. xii, fig. 
4; pl. xiv, figs. 4,5; pl. xix, fig. 7. 
Meandrina strigosa Dana, Pourtalés, Florida Reef Corals, p. 74; in L. Agassiz, 
Florida Reefs, pl. ix, figs. 6-9, 1880. 
Platygyra viridis Vaughan, op. cit., p. 306, plates ix—xiii, 1901 (non Lesueur). 
Meeandrina labyrinthica Duerden, Mem. Nat. Acad. Science, viii, pls. xx—xxii, 
figs. 138-147, anatomy and histology, 1902. 
This closely resembles the preceding in form and modes of growth 
and may become equally large and hemispherical, but the collines 
between the grooves are always narrow and not double. Its color in 
life is variable,—often pale ocher-yellow, sometimes dull brownish 
yellow, but so far as I observed it does not assume the bright orange- 
yellow color of the preceding species, nor have I seen it green, 
though Duerden reports specimens with green colors, due to an 
abundance of Zoéxanthelle in the endoderm. 
