98 CORALS AND CORAL LSLANDS. 



growth of three to five inches, above referred to, might have 

 been made during the three winter months. 



Duchassaing (in L Institute 1846, p. 117) observes that in 

 two months some large individuals of Madrepora prolifei-a^ 

 which he broke away, were restored to their original size. 

 More definite and valuable is the observation of M. L. F. 

 de Pourtales, that a specimen of Mceaiidi'ina labyrinthica, 

 measuring a foot in diameter, and four inches thick in the 

 most convex part, w^as taken from a block of concrete at 

 Fort Jefferson, Tortugas, which had been in the water only 

 twenty years. Again, Major E. B. Hunt mentions, in the 

 Ameriam Journal of Science for 1863, the fact of the growth 

 of a Moeandrina at Key West, Florida, to a radius of six inches 

 in twelve years, showing an average upward increase in this 

 hemispherical coral of half an inch a year, if, as is evidently 

 implied, this radius was a vertical radius. Major Hunt de- 

 posited specimens of corals of his collection near Fort Taylor, 

 Key West, in the Yale College Museum, and three of these 

 are labelled by him as having grown to their present size 

 between the years 1846 'and i8t)o, or in fourteen years. Two 

 are specimens of Oculiiia diffusa; one is a clump four inches 

 high and qight broad ; and the other has about the same 

 height. The weight of the first of these clumps is forty- four 

 ounces. The rate of four inches in fourteen years would be 

 equal to about 3^ twelfths of an inch a year in height, or 

 three and one-seventh ounces a year of solid coral. The other 

 specimen is of the Mcea?idrina clivosa V. ; it has a height of 

 tvvo-and-a-quarter inches, and a breadth of seven-and-a-half 

 inches. This is equivalent to about a sixth of an inch of 

 upward growth in fourteen years. The specimen weighs about 

 eighteen ounces. It is not certain that with either of these 

 specimens the germs commenced to grow the first year of this 

 interval, and hence there is much doubt with regard to these 

 calculations. 



The following observations are from a paper read by Prof. 

 Verrill before the Boston Society of Natural History in 1862. 

 The wreck of a vessel, supposed to have been the British 



