XXVI 
IXTEODTJCTIOX. 
during the progress of his work. He began under the influence of 
an idea which has attracted most workers on Eryozoa, and com- 
pletely fascinated some ; he believed that the zooecial characters 
were of primary importance, and that any sound classification would 
he based entirely on them. So he divided the Eryozoa into three 
Orders,^ the Bryo%oaires Cellulmes or Cellulince, the B. tuhulines, and 
the B. foramines ; the three Orders were founded on the characters 
of the zooecium or ^cellule,’ it being celluUe, tiibuUe, or forammee 
respectively. Eut d’Orbigny discovered by 1852 that a classification 
on zooecial characters alone was impracticable. He was forced to 
adopt a new classification,^ in which zoarial characters were given 
due and sometimes exaggerated value. He then adopted two orders, 
the Bryozoaires Cellulinh, with short zooecia growing in close 
juxtaposition, and the Bryozoaires Centrifuging, with very long, 
tubular zooecia, with a centrifugal growth. 
The groups were subdivided as follows : — 
Order CELLULINES. 
Suborder I. C. Eadicelles. Zoarium chitinous or semi- 
calcareous, and attached by chitinous or stoloniferous 
‘radicelies’ (roots). 
a. Kon-articulate. The Acamarchisidte, Flustridee, and Elec- 
trinidae. 
1. Articulate. Catenaridae and Cellaridae. 
Suborder II. C. Empates. Zoarium calcareous ; attached 
directly, without ‘ radicelles.’ 
Section 1. Zooecia with medium-sized aperture, not closed by 
chitinous membrane. Earn., Escharidae, Escharinellidae, 
Porinidae, Escharellinidae, Escharellidae, Porellidae, Porel- 
linidae, Eschariporidae, and Steginoporidae. 
Section 2. Zooecia with large aperture, closed by chitinous 
membrane. Earn., Elustrellaridae, Elustrellinidae, and 
Elustrinidae. 
Order CENTEIEUGHSTES. 
Suborder III. C. Eadicelles. Zoarium attached by stoloni- 
ferous, chitinous roots. Earn., Serialaridae and Crisidae. 
Suborder IV. C. Empates. Zoarium attached directly without 
roots. 
1 1851. Op. cit. pp. 22, 23. 
Op. cit. pp. 311 et sqq. 
