226 



CARNEGIE INSTITUTION OF WASHINGTON. 



Forites astreoides Lam. — The follo\ving table gives the size of young colonies 

 of Porites astreoides according to age: 



When practicable two diameters at right angles to each other were measured 

 in successive years, and the increments were ascertained by subtracting the 

 preceding from the later measurements. All increments for each species at 

 each station were added together and divided by the number of the annual 

 increments entering into the computation. The averages for height were 

 similarly determined. As the records are for annual growth-rate, each of the 

 Bahama records is counted as two, as each of those records represents a period 

 of two years. 



It should be said regarding the nomenclature of the species that the speci- 

 mens designated Mussa (IsophylUa) dipsacea Dana may include colonies of 

 M. (IsophylUa) fragilis Dana. The specimens referred to Porites clavaria 

 Lamarck may include more than one species of similar growth facies. 



