208 A. E. Verrill—The Bermuda Islands; Coral Reefs. 
muricata is particularly noteworthy, for the latter are often the 
most conspicuous of the corals on the West Indian reefs. One 
reason for their absence here may be the lower temperature of the 
water in winter. But it may be due in many cases to the short 
duration of the free-swimming larval stages* of such species, so that 
the young larve may all perish before arriving at Bermuda. The 
same causes have influenced most of the other marine animals. 
Probably most of the Bermuda species have migrated in one way 
or another from the Bahamas. How long a time is required for 
drifting objects to travel from the Bahamas to the Bermudas is not 
known. The distance is rather more than 700 miles, but floating 
objects would not travel in a straight line. They would, most 
likely, travel at least 1,000 miles in such a journey. At the rate of 
1 mile per hour the northward drift would be 1008 miles in 42 days, 
or 720 miles in 30 days. Probably the average rate of the current, 
in this region, may not be much greater than that. 
Verrill, Addison E.—Variations and Nomenclature of Bermudian, West Indian, 
and Brazilian Reef Corals, with Notes on various Indo-Pacific Corals (105 
pp., plates x-xxxv; 8 cuts in text). Trans. Conn. Acad. of Science, vol. 
xi, part I, pp. 63-168, 1901. 
Contains figures and descriptions of most of the Bermuda corals with details 
of synonymy, etc. 
Comparison of Bermudian, West Indian, and Brazilian Coral Faune, 
op. cit., pp. 169-206, cuts in text, 1901. 
Includes a list of all Bermuda corals then known. 
Zodlogy of the Bermudas, vol. i, 427 pp., 45 pJ., 1903. 
Includes the four preceding papers, as articles 5, 10, 11, 12. 
Amer. Jour. Science, vol. xiii, pp. 75-78, 1902. 
Relates to synonymy and changes in nomenclature, and contains the later 
views of Dr. Vaughan (note p. 76). - 
* Dr. J. E. Duerden has shown that many of the common reef corals, includ- 
ing some of those found at Bermuda, remain in the free-swimming larval condi- 
tion only a short time,—sometimes but few days. This adds very much to the 
difficulty of explaining their migration across wide seas. Possibly some corals 
may have drifted long distances attached to drift-wood or other floating objects, 
but it is rarely that they are found attached to drift-wood. I have seen a 
branched Oculina diffusa, over 6 inches high, taken from the bottom of a vessel 
at Bermuda, after a cruise in the West Indies. It is even possible that some of 
the common Bermuda corals were accidentally introduced into Bermuda waters 
by the vessels of the early settlers. Unfortunately the early writers on Ber- 
muda do not mention the existence of corals on the reefs. 
Review of The Stony Corals of Porto Rican Waters by T. W. Vaughan, 
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