290 A. E. Verrill—The Bermuda Islands; Coral Reefs. 
Zoanthus sociatus MeMurrich, Actin. Bahama Is., p. 62, pl. ii, fig. 3; pl. iv, 
figs. 15-18, 1889 (anatomy). Bull. Labr. Nat. Hist. Univ. Iowa, iv, p. 242, 
pl. iii, fig. 1, 1898 (anatomy); Zodlog. Bulletin, vol. ii, No. 6, mesenterial 
filaments, 1899. 
Zoanthus flos-marinus Duerden, Jamaican Actin., part i, p. 389, pl. xvii, fig. 
2, pl. xviiia, fig. 2, 1898 (non Duch. and Mich.).* 
Zoanthus sociatus Verrill, these Trans., x, p. 561, 1900. Duerden, Actinians 
of Porto Rico, p. 384, pl. ii, fig. 4, pl. iv, figs. 15,16; pl. v, figs. 17-22, 1902 
(anatomy). 
The polyps in this species are pedunculated; they arise from 
slender stolons and form open colonies. The column is clavate or 
enlarges upward to the disk, in expansion, and at the widest part is 
about 4 to 5™™ in diameter ; expanded disk, 5 to 8™™; height usually 
about 20 to 25™™, 
The tentacles are about 56 to 60 in adult polyps; they are small 
and rather slender, bluish green, olive, or brown. 
The disk is usually green, more or less varied with blue, yellow, 
or brown. There is sometimes a brown triangular spot at one or 
both angles of the mouth (t. MeMurrich and Duerden). The column 
is bluish, greenish, or dark violet above, yellowish below. 
The original figure of Z. sociatus in Ellis and in Ellis and Solan- 
der, if natural size, represents it as a larger species than the one now 
so-called. Moreover, one of the polyps is represented as expanded, 
and as having numerous long, slender tentacles, like an Epizoanthus. 
No measurements were given, and therefore it is doubtful whether 
the figure is natural size. If the drawing of the tentacles was cor- 
characterized by its large size, pedunculate form, and about 60 short, conical 
tentacles. But the early writers often measured and described their species of 
such animals from the drawings, not from specimens, and it may well be 
doubted whether either figure is natural size, for it is difficult to represent the 
small tentacles, ete. of these forms without enlargement. If such a common 
large species exists in the West Indies, it is remarkable that modern collectors 
have not found it. 
The species very fully described, 1898, with anatomical details by Duerden, 
under the name of Solandri, is a shorter and stouter species with cylindrical 
bodies and short stolons, similar to Z. proteus. 
* The Z. flos-marinus of Duerden, 1898, had much smaller polyps than the 
original type of Duch. and Mich., and differed in form, and in the size, color, 
and number of tentacles; the latter was described as having 36 tentacles (the 
figure shows 40). The flos-marinus of McMurrich, 1889, from Bermuda, seems 
to be my Z. proteus. No recent writer has noticed a large species 1.5 inches 
high, with 36 tentacles, corresponding with the original flos-marinus. 
