292 A, E. Verrill—The Bermuda Islands; Coral Reefs. 
monly divided into two regions by a slight constriction above the 
middle ; the lower part usually increases in size downward to the 
base; its substance is firm; the surface is longitudinally sulcated in 
contraction, somewhat rough, and usually covered more or less with 
foreign growths (diatoms, small sponges, ete.). The distal portion 
has a thinner wall, with a smooth, soft surface, and usually increases 
in size upward to the rounded summit; which is sulcated in contrac- 
tion. The expanded disk is broad, often convex, 7-9™™ in diameter. 
156 1387 138 
Figure 186.—Zoanthus Solandri Les., copied from Lesueur’s figure, } original 
size of figure. 
Figure 137.—Zoanthus dubius Les. Two polyps of the blue variety, expanded ; 
x about 14. 
Figure 158.—The same. Group of contracted polyps, enlarged about 23. The 
basal part of column is encrusted with living diatoms, etc. 
It forms somewhat open clusters; the polyps are united together 
by a thin membranous basal expansion, or by wide thin stolons. 
Sometimes the colonies are of considerable extent. 
The tentacles are short and vary from about 40 to 52. 
According to Duerden the lower part of the column is usually 
pale buff, while the upper part is olive-blue; disk bright green with 
lighter radial lines, sometimes pale green or yellow; lips often pink, 
sometimes red or yellow; sometimes a dark triangular spot at each 
angle of the mouth. 
Some of our specimens (as the one represented by fig. 137) were 
bright turquoise-blue all over the column; disk bluish green, or pale 
blue with green radii; lips reddish; tentacles 40-44, outer row green, 
inner ones bright blue. The cluster represented in fig. 138 had the 
column olive-green distally; disk pale ocher-yellow. Lesueur’s type 
had the disk green; mouth and tentacles yellow; body reddish. 
