BROWN, RUGOSE CORALS 
61 
mately radially placed as is shown in figure 19. In this same stage the 
pseudocolumella formed by the union of the inner edges of the septa is seen 
to have an opening in it. In figure 20, two additional pairs of secondary 
septa have appeared, one in the counter and one in the cardinal quadrants. 
A single opening is still present in the pseudocolumella. In the stage 
represented in figure 21, all the septa present in figure 20 have become 
nearly radially placed and a fourth secondary septum appears in one of the 
counter quadrants. The pseudocolumella here shows four distinct open¬ 
ings, one of which communicates with one of the interseptal spaces. 
In figure 22, a fourth secondary septum is well developed and reaches 
to the center in each counter quadrant, and a third secondary septum has 
started in each cardinal quadrant. The pseudocolumella can no longer 
be recognized as such. The inner margins of all the fully developed septa 
Figs. 17-24. Enterolasma caliculum. X 5. 
are now irregularly united. In figure 23, the continuity of some of the septa 
is broken, and the arrangement is irregular, while in figure 24, both of these 
characters are carried still farther, and at the same time the number of septa 
has been increased until now there are five secondary septa in each counter 
quadrant and four in each cardinal quadrant. The actual dimensions of 
the sections figured in figs. 17-24 are as follows: 17, 1.5 mm.; 18, 1.8 mm.; 
19, 2.0 mm.; 20, 2.3 mm.; 21, 3.5 mm.; 22, 4.5 mm.; 23, 5.5 mm.; and 
24, 8.0 mm. 
Other stages of the development of this species are shown in figures 25 
and 26. These were made and the septa identified in the following manner: 
The cardinal and alar septa were located by the arrangement of the costee 
on the exterior of the corallite. Then a fine India ink line was drawn down 
the side of the corallite, marking the positions of these three principal septa. 
