224 



CARNEGIE INSTITUTION OF WASHINGTON. 



much in height, while other species are adult when a diameter of 35 to 50 mm. 

 has been reached. Records of two species, Faviafragum and Moeandra areolata 

 illustrate relatively rapid growth for the first 2 to 4 years, after which it 

 decreases. Other species, for instance Orbicella annularis and Mceandra 

 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 the growth. 



A few species will be specially considered. 



Faviafragum (Esper). — The following table gives the size of colonies accord- 

 ing to age. The average annual increment is indicated by the number pre- 

 ceded by the + sign below that for the average size. The average most 

 rapid growth is during the first year, after which it declines, but should a speci- 

 men not attain an average size during the first year, it may grow rapidly 

 during succeeding years until it catches up to the average. (Compare speci- 

 mens Nos. 1 and 6 of the table.) 



Faviafragum — averages according to age. 



No. 



1 year old. 2 years old. 



Diam.! Height. 



3 

 4 

 5 

 6 

 17 

 18 

 9 

 10 

 11 

 12 

 13 

 14 

 15 

 16 

 17 

 18 

 19 

 20 

 21 

 22 

 23 

 24 

 25 

 26 

 27 

 28 

 29 

 30 



mm. 



11 



12.5 



19 



19 



19 



5.5 

 16 

 13 



9 

 10 



9 

 13 

 18 

 11 

 10 



9 

 10 



12.5 

 18.5 



6.5 



9 

 12 



9 

 10 



16.5 

 12 

 17 

 11 



mm. 

 4 

 4 

 6 

 5 



4.5 

 5 

 5 

 3 

 2 

 2 

 2 



Average.. 11.93 



3 years old. 4 years old 



Diam. Height. 



mm. 



27 



22.5 



31 



29 



31 



17.5 



19 

 17 

 11 



20.5 



20 



23.5 



25 



16 



11.5 



16.5 



15 



18 



15 



19.5 



24 



21.5 



15 



22.5 



18 



23 



13 



7 

 11 

 11 

 11 



8 

 10. 



9 



7 

 10 



4 



Diam. 



mm. 



30 



25 



33.5 



32.5 



36 



26.5 



20 

 26 



26 

 23 



9 I 27.5 



9 I 27.5 



9 I 



6 17 



5 19 



17 



5 



10 I 23 



i 27.5 



9 I 25 

 I 19.5 



6 ! 23 



7 1 22 



7 I 26.5 



3 I 



Height. 



Diam. 



mm. 



11 



10 



13 



14 



14 



13 



14.5 



11 



12 

 11 



10 

 6 



11 

 12 

 12 



mm. 



30.5 



26 



34 



33 



41 



32 



21 

 29 



31 



31 

 32 



26 



27 

 29 



28.5 

 31 



Height. 



mm. 



11 



11 



13 



16 



17 



16 



16 



11 

 10 



15 

 14 



5 years old. 



Diam. 



38 



33 

 34.5 



39 

 36 



Height. 



20 

 22 



15 

 13.5 



16 

 16 



14 

 15 



20.01 



(+8.08) 



7.9 

 (+3.90) 



25.14 11.46 

 (+5.13) (+3.56) 



30.13 



(+4.99) 



13.77 ! 34 

 (+2.31)(+4 



18 



71 { 17.21 

 58) (+2.44) 



'As 7 and 8 fused, separate measurements of the diameters became impracticable. 



