322 A. E. Verrill— The Bermuda Islands; Coral Reefs. 
shield-like tentacles and its sucker-feet are in three definite rows 
underneath. Its color is usually deep olive green. It lives under 
stones, like the last. 
Holothuria surinamensis Ludw. Sea Cucumber. Figure 172. 
Clark, op. cit., 1899, p. 121; 1901, p. 344. 
Holothuria floridana Heilprin, op. cit., p. 136, pl. xii, figs. 6, 6a, 7, 7a, 1889 
(non Pourtales). 
Common under stones and corals, both on the reefs and on the 
islands at low water mark. Similar to the last in appearance, but 
Figure 172.—Holothuria surinamensis, about natural size. Phot. from life by 
ACE ave 
longer. Color dull pale yellowish brown to dark olive-brown. The 
tentacles vary in number, but 20 is the most common number. 
ECHINOIDEA: SEA URCHINS.* 
The most abundant sea urchin is the dark purple or sometimes 
greenish species ( Towopneustes variegatus, see p. 146, fig. 40), which 
is to be seen almost everywhere on the white bottom of the lagoons 
in shallow water. It is sometimes found, also, on the reefs, though 
it is not a true reef species. It often covers itself with broken shells 
and other debris. 
Cidaris tribuloides (Lam.). 
Puate XXXIVa, Fic. 1. Puate XXXIVs, Fic. 2. PuatE XXXVI, Fig. 1 (11). 
This species is easily recognized by its stout cylindrical spines. 
It is not uncommon on the outer reefs, as in the vicinity of the 
* Three additional echini occur only in the bays on sandy or muddy bottoms. 
These are Melitta hexapora (see above, p. 146); Echinoneus semilunaris (under 
stones in sand near Hungry Bay); Brissus unicolor. 
