BROWN, RUGOSE CORALS 
59 
Corallum moderately small, cylindro-conical, usually straight, but sometimes 
slightly curved; calyx circular, moderately deep, sides thin; septal fovea obscure 
and in some species apparently obsolete; septa alternating in size, the larger ones 
continuing nearly to the center, having projections from their extremities which 
continue to the center, becoming much involved, forming a pseudocolumella of very 
peculiar appearance, somewhat resembling the convolutions of the intestines; sides 
of the septa with numerous papillate elevations or carinse, which in a transverse sec¬ 
tion give to the septa a crenulate or echinate appearance; tabulae and dissepiments 
present. The characteristic feature of this genus is the peculiar appearance of the 
pseudo-columella. 
Simpson lists as one of the species of this genus Streptelasma caliculum 
Hall, and the generic description applies in all but one particular. Entero- 
lasma caliculum does not have “papillate elevations or carinse” on the sides 
of the septa. Instead, the cross section shows the septa to be smooth and 
straight until they become involved in the peculiar pseudocolumella. In 
the individual studied, although the septa are somewhat irregular at the 
center, they do not seem to have projections forming the peculiar pseudo¬ 
columella described above. It appears rather that the pseudocolumella is 
incomplete or imperfectly formed, and under certain circumstances gives 
this peculiar appearance from which Simpson gives the name Enterolasma. 
Enterolasma caliculum is described by Hall as follows: 
Turbinate, oblique or curved, more or less rapidly expanding by the addition of 
interstitial rays; cup moderately deep; rays or vertical lamellae about half the 
thickness of the space between them, from 20 to 50, ordinarily about half this num¬ 
ber, more or less curved toward the center; external surface with the lamellae very 
distinct and marked by transverse striae; surface rarely corrugated; rays alternating 
with short dentations on the inner margin of the cup ( loc. cit.). 
This species occurs throughout the middle Siluric but is found most 
abundantly in the upper part of the Clinton beds and in the Rochester Shale. 
It is a coral well adapted for the study of its ontogeny in all except the very 
youngest stages. Perfect tips are hard to obtain; nevertheless, a very young 
stage has been found, and all stages of development from this to the adult 
have been carefully traced. 
A small individual of this species was obtained from the matrix about a 
larger individual. The stages of development observed in this very small 
specimen are shown in figures 11-16. The fractured end, as it was wdien 
removed from the matrix, showed five septa (figure 11). After grinding 
a little a sixth septum appeared (figure 12). The cardinal, counter and alar 
septa were located by the arrangement of the costae or external ridges of the 
