RATE OF GROWTH OF CORALS. 125 



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

 Journal of Science for 1863, the fact of the growth of a Moean- 

 drina 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 deposited speci- 

 mens 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 1860, or in fourteen years. Two are speci- 

 mens of Oculina diffusa; one is a clump four inches high 

 and eight 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 Mceandrina clivosa V. ; it has a height of two 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 frigate Severn, lost in 1793 near " Silver Bay," off 

 Turk's Islands, is covered with growing corals. It lies (accord- 

 ing to the journal of Mr. J. A. Whipple, by whom specimens 

 were collected in 1857) in about four fathoms of water. One 

 of the specimens was a mass of the species Orbicella annula- 

 ris, shaped somewhat like a hat ; it is attached to the top of a 



