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IOWA ACADEMY OF SCIENCE Voi.. XXVII, 1920 
Colonies arising by Budding. Caryophyllia is an example of 
imperforate solitary coral, and what has been said about Balano- 
phyllia applies also to Caryophyllia. 
Haploheiia, an Oligocene genus in the family Oculinidae, stands 
as an example of primitive dendroid colony, having gemmation 
from one side only. In Oculina the corallites are small and numer- 
ous, arranged spirally or scattered irregularly over the branches 
and imbedded in coenenchyma — ■ obviously an advance over 
Haploheiia in colony- formation. 
A reduction in size of corallites and filling in of coenenchyma 
is to be found in the family Orbicellidae. Galaxea forms a sub- 
massive colony with exsert turbinate calices, while in Orbicella the 
calices are smaller and imbedded in coenenchyma; the latter con- 
dition must be interpreted as a marked advance over the former 
in colony-evolution. 
Colonies arising by Fission. Lophohelia is an example of a 
primitive dendroid colony. The geniculate branching indicates 
that the colony results from simple successive unequal fissions, the 
original turbinate shape typical of the solitary corals being re- 
tained by each calice. Other colony-formation by fission is illus- 
trated by the three families Busmiliidae, Mussidae, and Baviidae. 
Busmilia forms cespitose colonies by dichotomous or trichotomous 
fission, but the rapid separation of the corallites with upward 
growth is accompanied by withdrawal of soft parts, leaving the 
colony complex only as to skeleton. The soft parts are continuous 
between members of the last division, so as a rule the polyps are 
confluent in twos , and threes. In Dichocoenia the same division 
into two or three calices occurs, but reduction in size of calices 
and filling of intercalicinal spaces with coenenchyma results in a 
massive colony in which all soft parts are continuous and the 
calices are confluent in small groups. 
In Mussa sinuosa fission results in a meandrine form, but the 
walls of confluent groups are ununited, leaving the soft parts of the 
individual groups distinct. In Diploria the walls of the adjacent 
series of corallites are united by the peripheral ends of costae, 
which leaves a shallow trough, over which, however, the polyps 
are continuous. In Meandrina the fusion of the walls directly 
into a single colline brings about the highest union between the 
soft parts of an entire head that is to be found throughout the 
whole group Aporosa. 
Fungida. In the Fungida it was not found possible to follow 
out the two lines of colony formation because of incomplete data 
