CORALS AND CORAL REEFS — VAUGHAN. 213 



Size of colonies of I'orites astreoides — averages according to age. 



Tables giving the summaries of my work on the growth-rate of 

 the Floridian and Bahaman corals have been published in the papers 

 cited in the footnote. 1 The growth-rate of 25 species was investigated, 

 and a total of some thousands of measurements were made. Of 

 course, as no such mass of data can be presented in this place, a few 

 general statements must suffice. 



The size of the colonies of all species of corals seems limited, 

 but some attain large dimensions, 2 to 3 meters or even more in 

 diameter, and nearly as much in height, while other species are 

 adult when a diameter of 35 to 50 millimeters has been reached. The 

 records of Favia fragum and Maeandra areolata illustrate relatively 

 rapid growth for the first two to four years, after which it decreases. 

 Other species, for instance, Orbicella annularis and Maeandra, strigosa, 

 are not so limited in size. Ramose corals increase in dimensions more 

 rapidly than massive species; while of the former, the growth-rate 

 of species with perforate, loose-textured skeletons is more rapid than 

 that of those with dense skeletons. In general the more massive 

 and the denser the corallum, the slower the growth ; while the more 

 ramose and the more porous the skeleton, the more rapid theg rowth. 



1 Vaughan, T. W., The geologic significance of the growth-rate of the Floridian and 

 Bahaman shoal-water corals : Washington Acad. Sci. Jour., vol. 5, pp. 591—600, 1915 ; On 

 Recent Madreporaria of Florida, the Bahamas, and the West Indies, and on collections 

 from Murray Island, Australia : Carnegie Institution of Washington Yearbook No. 14, 

 pp. 220-231, 1916. 



65133°— sm 1917 15 



