BROWN, RUGOSE CORALS 
55 
interpret this species as having four primary septa and bilateral pairs of 
secondary septa added simultaneously or almost simultaneously in the 
counter and cardinal quadrants, allows Streptelasma profundum to fall in 
line with all the other species of this and allied genera. The interpretation 
Figs. 1-5. Streptelasma profundum. X 4. 
of it as an original hexamerous form would make it an anomaly that will not 
bear comparison with other rugose corals. 
In the adult corallite of Streptelasma profundum a condition is found 
that is characteristic of the developmental stages of other later species. 
Only a few of the septa reach the center. The others extend down the 
interior of the cup, those in the counter 
quadrants in a direction as if they 
would run into and unite with the 
dorsal side of the alar septa, and those 
in the cardinal quadrants as if they 
would unite with the cardinal septum 
on either side. But instead of reaching 
and uniting with the primary septa, 
the inner margins of the secondary 
septa are bent so that they unite, each 
one respectively with the secondary 
septum immediately preceding it in 
the order of appearance and dorsal to 
it in position in the corallite. This 
Fig. 6. Streptelasma profundum. X 4. gives, when looking down into the 
cup, the condition shown in figure 6. 
All the secondary septa are united in a pinnate manner by their inner mar¬ 
gins and leave a well-defined open space along either side of the cardinal 
septum and a space on the dorsal side of each alar septum. 
In so far as can be observed in the surface views the tertiary septa appear 
