60 
ANNALS NEW YORK ACADEMY OF SCIENCES 
calyx. The individual corallites of this species are, as a rule, so perfect and 
symmetrical, and the costpe on the exterior show so clearly that there can 
be no doubt about the orientation of the individuals and identification of the 
septa. This sixth septum comes in between the counter and alar and at 
first extends only from the wall to the dorsal side of the alar septum. As it 
becomes more and more fully developed the point of apparent union of this 
septum moves along the dorsal side of the alar septum until it becomes radially 
situated (figure 13). The individuals of this species develop very rapidly 
in their early stages, and a very small amount of grinding off at the tip brings 
out the successive developmental stages. A little further grinding showed 
Figs. 11-16. Enterolasma caliculum. (Enlarged.) 
another secondary septum beginning to appear in one counter quadrant 
(figure 14), and still further grinding showed a corresponding septum in 
the other counter quadrant, and at the same time a secondary septum began 
to arise in one cardinal quadrant (figure 15). This cardinal quadrant sep¬ 
tum came in as a short septum extending from the wall of the calyx to the 
ventral surface of the alar septum, and as it developed, the apparent point of 
attachment of the inner margin moved inward toward the center of the 
calyx. The next stage in the development shows two secondary septa in 
each counter quadrant and one in each cardinal quadrant (figure 16). 
As this individual was very small, the later stages of development could 
not be followed in it, but another individual was found showing eight septa 
on the fractured tip (figure 17) and the successive stages in the development 
of this were followed until the corallite reached a diameter of 8 mm. 
In the fractured tip of this individual, eight septa are present, and accord¬ 
ing to their relation to the costae on the exterior of the calyx these are inter¬ 
preted as the cardinal, counter, two alar and two secondary septa in each 
counter quadrant. Grinding it down to the next stage (figure IS), a pair 
of secondary septa arise in the cardinal quadrants. These are short at first 
and apparently united with the ventral side of the alar septa. As they 
develop, the point of apparent attachment moves in till they become approxi- 
