A, E. Verrill—The Bermuda Islands; Coral Reefs. 243 
it abundant on the shallow flats at Long Bird Island, even in places 
laid bare at low tide, and also at Walsingham Bay in one or two 
feet of water in a sheltered, muddy cove. In such places it often 
forms ovate or subglobular masses, 3 to 6 inches in diameter, wholly 
unattached, and with calicles on all sides. They were evidently 
attached, when very young, to small shells or loose bits of stone 
which have been entirely enclosed. On the reefs it forms thick 
crusts or more or less hemispherical masses, up to more than a foot 
in diameter. 
In life the color is usually dull orange-brown, or brownish yellow, 
or sometimes clay-color, varying according to the situation. In full 
expansion the polyps rise only a little above the calicles. The tenta- 
cles, about 36 in number, are scattered over about one-half the disk, 
forming three or four irregular circles ; they are mostly small, slen- 
99 100 
Figure 99.—Siderastrea radians, group of calicles, x 24. 
Figure 100.—S. siderea. Calicles, x24. Both phot. by A. H. V. 
der, tapered, but the larger inner ones are bilobed. In 1898, I did 
not see that the tips were bilobed, as they were figured by L. 
Agassiz many years ago,* but his enlarged figure (5) does not show 
bilobing, but indicates that the appearance was due to their peculiar 
grouping, which the artist did not understand. The coenenchyma is 
marked by lighter and darker radial lines of color, the disk is often 
dark orange-brown or yellowish brown, with paler radial lines ; lips 
lighter ; tentacles yellow or yellowish brown with whitish enlarged 
tips. 
* Duerden has, however, recently described them as bilobed at the tip (op. 
cit., 1904, p. 10). They are small and may have been imperfectly expanded 
when observed by me, but it is possible that they vary in this respect. Accord- 
ing to Dr. Duerden they are dimorphic, the inner ones, which are endoceelic, 
being bilobed, while the outer ones are ectocwlic and simple. (See figs. 99a, 
99d.) 
