WEST INDIES. 
271 
all these banks ; namely, the accumulation of sediment, 
conjoined with an elevatory movement, and the growth of 
coral on their outer edges. The parts which are fringed 
by living reefs are coloured red. — Westward of these banks 
there is a portion of coast apparently without reefs, except 
in the harbours, the shores of which seem in the published 
plans to be fringed. — The Colorado Shoals (see Captain 
Owen’s charts), and the low land at the western end of 
Cuba, correspond as closely in relative position and struc- 
ture to the banks at the extreme point of Florida, as 
the banks above described on the north side of Cuba 
do to the Bahamas. The depth within the islets and 
reefs on the outer edge of the Colorados, is generally be- 
tween two and three fathoms, increasing to 12 fathoms in 
the southern part, where the bank becomes nearly open, 
without islets or coral-reefs ; the portions which are fringed 
are coloured red. — The southern shore of Cuba is deeply 
concave, and the included space is filled up with mud and 
sand-banks, low islands and coral-reefs. Between the 
mountainous Isle of Pines and the southern shore of Cuba, 
the general depth is only between two and three fathoms ; 
and in this part, small islands, formed of fragmentary rocks 
and broken madrepores (Humboldt, Pers. Narr. vol. vii. pp. 
51, 86 to 90, 291, 309, 320), rise abruptly, and just reach 
the surface of the sea. From some expressions used in the 
Columbian Navigator (vol. i. pt. ii. p. 94), it appears that 
considerable spaces along the outer coast of southern Cuba 
are bounded by cliffs of coral-rock, formed probably by the 
upheaval of coral-reefs and sand-banks. The charts re- 
present the southern part of the Isle of Pines as fringed by 
reefs, which the Columb. Navig. says extend some way from 
the coast, but have only from 9 to 12 feet of water on 
them ; these are coloured red. — I have not been able to pro- 
cure any detailed description of the large group of banks and 
‘ cays ’ further eastward on the southern side of Cuba ; 
