“Oribrimorph” Cretaceous Polyzoa. 83 
has this advantage, that each successive stage is left behind 
and not, as a rule, covered over or obscured by further 
growth. 
A. Pelmatoporide, fam. nov. 
Diagnosis. Multiserial Cheilostome Polyzoa of moderate 
or large size (4 mm. to 1? mm.), whose intraterminal front 
wall is typically built of hollow terminal spines bent over 
archwise, fused in the middle line, then bent vertically and 
continued as free spines, the broken ends of which form 
two rows of pelmata (if smail, pelmatidia)—hobnail-like 
markings on the intraterminal front wall; lateral costal 
fusions and secondary pelmata or pelmatidia may be 
developed ; apertural spines typically 4, but occasionally 
5, 6, or 7; a secondary aperture generally attained, and 
by a variety of methods in the different lineages ; avicularia 
primarily small and abundant (seldom absent), but may 
become, secondarily, of a considerable size. 
Tabular Diagnoses of Subfamilies of Pelmatoporide. 
A. Coste thin, with a single series of pelmatidia 
and no lateral costal fusions. 
I. Costz separated by wide gaps ........ a, Francoporine. 
II. Costz touching or very close together. 
a, Avicularia occasional, rather large, and 
pointing obliquely proximally ...... b. Opisthornithoporine, 
6, Avicularia generally abundant and not 
generally proximally directed. 
1. Each half of the apertural bar bifid.. c. Kelestomine. 
2. Apertural bar not bifid. 
a, Avicularia, if emerging from se- 
condary tissue, are either several, 
placed around the aperture, or a 
pair laterally or proximally placed 
with regard to the aperture ....  d. Tricephaloporine. 
8. A pair of avicularia, distally placed 
with regard to the aperture, 
emerge from secondary tissue 
which envelops the whole cecium 
otherwise, except the aperture 
and a small part of the intrater- 
minal front wall; proximal aper- 
tural spines fuse with a median 
process of the apertural bar and 
with the distal apertural spines, 
forming a pair of hoop-like arches 
on each side of the aperture ..., e. Pnictoporine. 
B. Coste thin, with secondary pelmatidia and 
lateral costal fusions ...,....... OCU f, Castanoporine. 
6* 
