NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
593 
The ovicell is recumbent. The budding is double, terminal and superficial. 
The zooecia are more or less erect and cumulate. 
Figure 176 illustrates the anatomical knowledge of this important family. 
The only known larva is of the schizostomatous group. Levinsen in 1909 
created a special family for the holostomatous group, which is perhaps a valid one, 
but as we are ignorant of the larva we have not recognized it. Our clithridiate 
group is perhaps also a distinct family. 
The budding is superficial ; it occurs on all the zooecial walls. Certain frontal 
pores are therefore not areolae but veritable septules. The consequence is the piling 
up or accumulation of the zooecia. In the distal budding the zooecia are always 
oriented ; in the superficial budding they are arranged in all directions. However, 
the zooecia issuing from the- larva and those which are in contact with the sub- 
stratum are always oriented. In some rare fossil species the cumulate zooecia are 
rare. The power of superficial budding is then apparently not spontaneous, but 
it is generalized gradually. 
Among the Cheilostomes the Cellepores have appeared last (about the Lutetian) 
and in the tropical seas. They are multiplied to excess in the Miocene. At pres- 
ent they have overrun the seas, where often they multiplied in immense numbers; 
they dominate the recent fauna by their extraordinary numbers. In the size of 
rlieir zoarium, the extreme rapidity of their budding, the infinite pliancy of their 
aptitude for adaptation, and in their astonishing fertility, they show an over- 
whelming vitality. They accommodate themselves to all areas, to all depths, to all 
temperatures, and to all kinds of foods. These are the most vigorous and the most 
perfected of all the bryozoa. 
Historical . — An authoritative history of the genus Cellepora was given in 1852 
by D’Orbigny. 1 He attributed it to Fabricius, 1780; this it appears was an error 
that Hincks repeated later; Levinsen, in 1909, noted that its founder was Linnaeus 
himself, in 1767. In 1913 Waters rewrote the history with a scrupulous exactitude; 
his conclusion was that the interpretation of the poor figui’es of the early authors 
lias caused most vexatious confusion and that it is more scientific to adopt the types 
of Busk and Hincks, who recognized the true nature of the bryozoa. 
It was in 1836 that Milne-Edwards, in the second edition of “Animaux sans 
vertebres” of Lamark, gave the name of Cellepores to the species with cumulate 
zooecia. Whether wrong or right, this opinion has prevailed in the science. There 
has been nothing of scientific interest added to the discussion after three-quarters 
of a century. Moreover, the word indicating only a special and complex mode of 
budding, ought necessarily to disappear from the generic nomenclature, since by 
definition even, a genus is a union of creatures having the same functions, the bud- 
ding being only one of these functions. 
We have preserved the word Cellepora as an invalid genus only for the species 
requiring further study, as we are often forced to do in paleontology. 
1 Paleontologie frangaise, Terrains Cretaces, p. 3S9. 
55899— 19— Bull. 106 38 
