ZOOLOGY: L. R. GARY 
287 
of twenty analyses were made of the gorgonians growing upon a square 
yard of the surface of widely separated reefs. The bulk of the gorgoni- 
ans varied from 1.5 pounds to 25.0 pounds, the spicule content from 
0.45 pounds to 6.94 pounds, for the different squares. The average for 
all determinations was 7.746 pounds of gorgonian colonies containing 
2.1225 pounds of spicules. 
2. Distribution of gorgonians on the reefs about Tortugas. To determine 
the distribution of the species of gorgonians included in the foregoing 
analyses on the reefs about Tortugas a series of lines were laid out ex- 
tending over a number of the most important reefs and along these 
lines counts of the number of gorgonians occurring on a square yard 
were made at regular intervals, with the following results : 
Average Number 
Squares number barren 
oj colonies squares 
Line No. 1 45 5.72 8 
Line No. 2 150 8.97 14 
Line No. 3 30 10.86 3 
Line No. 4 25 7.62 1 
Line No. 5 40 13.27 7 
Line No. 6 36 5.86 5 
In these counts the number of colonies was alone recorded for each 
square yard. The weight of the mass of gorgonians on any square was 
estimated upon the basis of the determinations shown in the second 
column of the first table in which the figures represent the average 
weight for twenty medium sized colonies of each species. 
Computed upon this basis the average weight of the gorgonians from 
each square along Hne No. 1, as given above, is 7.32 pounds. Estimat- 
ing the spicule contents on the basis of the figures obtained from the 
analyses recorded in the table it is shown that there would be two pounds 
of spicules in the gorgonians from any square yard of reef area along this 
line. This result approaches very closely the amount found by actual 
analyses of the colonies from twenty representative squares. The num- 
ber of colonies to the square along this line was the smallest found in 
the counts on any of the reefs so that when estimated upon the same 
basis the spicule content of the gorgonians on the squares along the lines 
on any of the other reefs would be greater than that found by actual 
analyses for the twenty squares previously mentioned. Using the 
smaller figure, which is well below that obtained by careful observation, 
the amount of lime held as spicules in the tissues of living gorgonians on 
a representative acre of reef area is 5.28 tons. 
3. Disintegration of the gorgonian colonies and the addition of their 
spicules to the reef building materials. The spicules held in the tissues 
