ceagin.] DESCRIPTIONS OF SPECIES. 35 
"The above represents the type form of the corrallum. There is 
one specimen, with a mammillate surface, which shows no place for 
attachment, and other specimens show a tendency to form low 
columns. 
" The corallites are polygonal, usually hexagonal, are crowded 
together, and are joined by their directly fused walls. The Avail 
between adjoining corallites is usually thin, but in some instances it 
may be rather thick, in extreme cases almost 1 mm. When the wall is 
thin, its upper edge is acute; when it is thick, it is flattened between 
adjoining calices. The depth of the calicular cavity is so variable 
that it possesses no value in the specific diagnosis; it is sometimes 
deep and sometimes very shallow in the same colony. The diame- 
ter of the calices vary in the same colony from 1.5 to 2.5 mm. The 
minimum diameter for a calice is 1 mm. and the maximum is about 3 
mm., or a very little less. The number of septa is 16 or 20. There are 
either 8 or 10 principal septa, with smaller ones between. At their 
margins the septa are usually rather thin, but deeper down in the 
corallite are secondarily thickened. The septa are thicker periph- 
erally at the Avail and are also thickened around the columella. The 
septa of adjoining corallites meet end to end or alternate with each 
other. In transverse sections of corallites dissepiments are very 
rarely present. No further information can be given concerning 
the endotheca. The columella is small, Ioav, weak, and styliform. 
Below the bottom of the calice it is strengthened by having the 
thickened inner terminations of the principal septa fuse around it. 
Gemmation takes place in the angle between adjoining corallites. 
" There is another specimen not included in the above. It is an 
Astroccenia, apparently growing in digitate branches. There is not 
enough material to warrant naming and describing it." 
ECHINODERM^T^. 
ECHINOIDEA. 
HOLECTYPOIDA. 
Genus HOLECTYPUS Desor. 
HOLECTYPUS? Sp. 
An echinoid fragment indicating a test shaped as in this genus, but 
with the details too poorly preserved to alloAV a satisfactory descrip- 
tion or an absolute generic identification, Avas obtained by Doctor 
tanton from an anticline on the east slope of Malone Mountain, 
ibout 1 mile north of the southern end. 
