BRANNER: THE STONE REEFS OF BRAZIL. 257 
“Tn lithological characters the Abrolhos beds resemble the sandstones, etc., 
of the Rio São Francisco at Penedo, . . . and which contain similar plant 
remains. They have been disturbed by the same upheaval, and I have little 
hesitation in referring both to the cretaceous. . . + 
“ As we go northward from Cape Frio, the madreporians become quite com- 
mon on the rocky shores, though the species are not numerous, and they are 
associated with species of Millepora, Zoanthus, and Palythoa, and various gor- 
gonians. 1 have already called attention to the coral fauna of Guarapary and 
Victoria, and I have stated that I have no evidence of the existence of any 
banks of living corals or reefs south of the region of the Abrolhos. Here the 
conditions for the growth of coral reefs on a large scale are remarkably favor- 
able. Over large areas the water covering the great submarine shelf, on which 
the islands are based, is much under one hundred feet in depth, and it is 
warm and pure. So it is not to be wondered at that very large coral reefs, 
both fringing and barrier, are found here. 
“ When the tide goes out there is seen extending round about one half the 
circumference of the island of Santa Barbara a fringing reef. . . . One may 
then walk out on its level surface as on a wharf, and from its ragged edge 
look straight down through the limpid green water and see the sides of the 
reef and the sea bottom covered with huge whitish coral-heads, together with 
а wealth of curious things not to be obtained without a dredge. 
“The surface of the reef, though flat, is somewhat irregular. It rises but a 
short distance above low-water mark, and it is overgrown with barnacles, 
shells, mussels, and serpula-tubes, together with large slimy patches of the 
common leather-colored Palythoa. The reef abounds in small pools, some 
shallow and sandy, others deep, rocky and irregular. The former often con- 
tained scattered masses of corals, particularly Siderastraca and Favia, and they 
abound in small shells, crabs, Ophiurae, ete.; but the deep pools are the 
richest in life. These are usually heavily draped on the sides with brilliantly 
tinted sea-weeds and corallines, the bare rock being gay with bryozoa and 
hydroids. The most common coral of these pools is Siderastraea stellate 
У... 
“ The material composing the reef is an exceedingly hard, whitish limestone, 
ringing under the hammer, and, so far as I had an opportunity to examine it, 
for the Brazilian reefs are never broken up by the surf, — showing no distinet 
trace of organic structure. The Santa Barbara reef extends around about one 
third of the island, and on the northwestern side it reaches across to the 
* Cemetery, so that when the tide is down that islet is joined to the main 
island by a broad, level platform of rock, diversified by tide-pools, and form- 
ing an excellent, collecting-ground for the naturalist. The reef, built up prin- 
cipally of Acanthastraca, Siderastraca, etc., has completed its erowth on arriving 
at low.tide level, the upper surface being still farther added to by serpulae, 
bryozoa, corallines, barnacles, etc., together with the coral-sand and debris of 
shells accumulating on the reef, 
“So far I have spoken only of fringing reefs, but there are other coral 
VOL. XLIV. 17 
