BRYOZOANS FROM CHATHAM ISLAND 
bars), but the surface expression of the peristomial orifices, areolar 
pores, and range of avicularian sizes of K. grandis Canu & Bassler 
has much in common with that of Beisselina. Kleidionellidae 
Vigneaux is therefore used here rather than create a separate family 
for Beisselina and similar forms. 
Beisselina has not previously been associated with Kleidionella 
and the two genera would not historically have been associated 
because of the lack of a spiramen in the latter. The presence/absence 
of a spiramen need not require segregation at the family level, 
however, as evidenced by the following genus pairs: Beisselina / 
Pseudobeisselina, and Beisselinopsis | Pavobeisselina. Pseudo- 
beisselina compressa (Goldfuss), type and only species of the genus, 
37 
was formerly classified in Beisselina until it was discovered that it 
lacks an ‘ascopore’ — ‘Sinus oder Spiramen, keine Ascopore’ 
(Wiesemann, 1963: 51). Beisselinopsis and Pavobeisselina both 
have rooted fan-shaped colonies (by which they differ from 
Beisselina) but the former lacks a spiramen and the latter has one. In 
umbonuloid-shielded cheilostomes, however, it is a relatively sim- 
ple matter to convert a peristomial pseudosinus into a spiraminal 
tube (this is how a spiraminal tube is formed ontogenetically) and 
there appears to be no intrinsic reason why, if other morphological 
characters conform, apparently related genera should be segregated 
on the basis of the spiramen alone. Traditionally, a pore associated 
with a peristome has been termed a spiramen, whereas a pore more 
Figs 96-99 Hippopleurifera australis sp. nov., IGNS BZ 199, holotype. 96, disposition of zooids, x 58. 97, autozooids; note the appearance of paired 
spine bases at the sides of the orifices, x 106. 98, avicularia adjacent to the orifice (distal is towards the bottom of the photo), x 119. 99, autozooids; note 
the areolar pores in the steeply descending cormidial orifices, x 116. 
