290 The American Geologist. November, 1897 
merely disorderly union. It is not apparent tliat the "twist- 
ing" of the septa has any other meaning tfian that irregular 
peripheral growth of the theca and slight deviation in the nu- 
merous septa caused confusion in the centre where the septa 
converged. Obviously this is the explanation of the confu- 
sion within the early attached portion of the cell, since one 
side of the cell is distorted and the corresponding septa are 
disturbed. In tranverse section, it may be added, the septa 
are not cut at a single stage of their development and in the 
tabulate portion where the septa are unequal in size above and 
below each tabula, and are moreover strongly serrate, the ap- 
pearance of "twisting together" is really exaggerated. Also 
in natural casts many of the tabuliB and parts of the septa 
had as a rule been destroyed by masceration and a false im- 
pression is gained. 
The cell opening is rarely if ever preserved in its exact nat- 
ural form. The septal margins converged downward (tig. 7, 
pi. XVII) however and neared the centre most rapidly at the 
base of the ealyclo, nearly as usually seen in good specimens. 
The direction of the tabulae proves further that the inter- 
septal spaces were not deepest in the centre of the calyclebut 
that the calycle as a whole had a more or less upwardly con- 
vex, broad bottom from beginning to end of its growth. 
At the base of the calycle in mature specimens a fossula 
or pair of fossula? is easily observed. On either side of the 
cardinal septum are irregular pits each displacing the ex- 
treme, free edges of one to three major septa, and connected 
by a small depression over the edge of the cardinal septum, 
which however is not displaced nor shortened thereby as far 
as observed. The cardinal septum is the longest one as a 
rule. On the posterior side of the alar septa are correspond- 
ing pits which although single and narrow, must apparently 
also be called fossulse. in thin sections they are not easily 
made out but on casts and silicitied specimens they can be 
seen. Young specimens do not appear to have fossuhe but 
since the fossulne are often inconspicuous and develop gradu- 
ally it is ditficult to determine at what stage they begin. 
Conclusion. 
There appears to me to be nothing in the above described fos- 
sils upon which can or should be based a distinction of them 
