BRYOZOANS FROM CHATHAM ISLAND 
Family ASPIDOSTOMATIDAE Jullien, 1888 
Genus ASPIDOSTOMA Hincks, 1881 
TYPE SPECIES. Aspidostoma crassum Hincks, 1881 = Eschara 
gigantea Busk, 1854, by monotypy; Recent, SouthAtlantic, Patagonia 
to Gough Island and the Antarctic Peninsula. 
Aspidostoma litotes sp. nov. Pig. 64 
HOLOTYPE. IGNS BZ 191, from Pukekio, Chatham Island. 
NAME. From the Greek, /itotes, f., plainness, simplicity. 
DESCRIPTION. Colony erect, cylindrical, evidently bifurcating, 
0.54—0.80 mm diameter. Autozooids arranged in 5-8 longitudinal 
rows, the number of rows increasing distally, by row bifurcation, as 
a stem thickens. Autozooid length = 0.56—0.86 mm, width = 0.35— 
0.45 mm. Zooids widest in the vicinity of the orifice, each with thick, 
raised, rounded lateral rims that converge distally around the orifice. 
Frontal cryptocyst between the rims sloping towards the orifice, the 
surface granular where well-preserved. Opesia-orifice subrounded, 
the centre of the proximal rim gently concave with a tiny projection 
on each side defining a very small opesiular indentation. Avicularia 
and ovicells not seen. 
REMARKS. Although lacking avicularia and ovicells, the zooidal 
and orificial characters of this species are similar to those of 
Runangan-Whaingaroan (Priabonian-Rupelian) Aspidostoma 
curvatum Uttley, 1949 and A. turricula Brown, 1952 from Oamaru 
which, however, have orifices opening on one face only. The lack of 
avicularia may be a genuine feature of A. litotes, or they may simply 
be rare as in A. turricula. There are some superticial similarities 
between A. litotes and a species from the Paleocene of Surinam 
described by Lagaaij (1969) as ‘Vincularia’ cristata. However, the 
opesiae of Lagaaij’s species have small pectinate denticles. 
Aspidostoma cinnabarina sp. nov. Figs 65-70 
HOoLotyPeE. IGNS BZ 192, from Pukekio, Chatham Island, en- 
crusting a bivalve shell. No paratypes. 
NAME. From the Latin cinnabaris, cinnabar, and Greek 
kinnabarinos, red like cinnabar, alluding to the red-coloured tuff at 
the type locality. 
DESCRIPTION. Colony encrusting, large. Autozooids large, arranged 
quincuncially; length typically about 1 mm but ranging from 0.39 
mm in zooids from zone of change to 1.14 mm in abnormal zooids; 
width usually 0.54-0.57 mm, but ranging from 0.45 mm in zooids 
from zone of change to 0.78 mm in zooids preceding row bifurca- 
tions. Frontal wall ventricose, sloping evenly all round, including 
distal to the orifice, into the deep interzooidal furrows, the surface 
regularly and evenly coarsely granular, the raised granules tending 
to be arranged into polygons so that the overall surface appears 
dimpled; there is a very slight elevation of the frontal wall immedi- 
ately proximal to the orificial region. Opesia-orifice transversely 
narrow, the proximal rim straight with no or vestigial indentations at 
the corners, the distal rim and lateral peristome raised, with irregular 
tuberculation or processes; no oral spines. Small interzooidal 
avicularia occur generally sporadically, each at the junction of three 
autozooids, narrow with a narrow acute rostrum orientated proxi- 
mally in the direction of the furrow; no apparent crossbar or condylar 
ridges. Ovicells hyperstomial, somewhat cucullate, the lateral mar- 
gins raised, relatively straight and somewhat converging, the proximal 
rim tending to project over the opesia-orifice; external calcification 
interpreted as endooecium, relatively smooth. Basolateral septular 
2, 
communication pores set in narrow-buttressed recesses that simu- 
late pore-chambers, budding intrazooidal in the terminology of 
Lidgard (1985). Reparative budding common, and autozooids with 
reversed orientation or completely closed and often kenozooidal. 
REMARKS. Aspidostoma cinnabarina has virtually all of the char- 
acters typical of the Recent subantarctic type species of the genus, 
except for its overall robustness because of thick calcification, and 
appears easily accommodated in the genus. The interzooidal 
avicularia of the type species have a separate opesial foramen and 
are orientated obliquely distally, but these characters may be rela- 
tively trivial at the genus level in Aspidostoma. 
Family CELLARIIDAE Fleming, 1828 
Genus CELLARIA Ellis & Solander, 1786 
TYPE SPECIES. Farcimia sinuosa Hassall, 1841, by synonymy (see 
Ryland 1968); Recent, NE Atlantic. 
Cellaria minus sp. nov. Figs 71-73 
HOLOTYPE. IGNS BZ 193, from Pukekio, Chatham Island. No 
paratypes. 
NAME: From the Greek, minus, little, small, short. 
DESCRIPTION. Colony erect, evidently articulated in life, the 
internodes extremely slender, straight, 0.27-0.28 mm diameter. 
Autozooids alternating, in six longitudinal series, proportionately 
elongate and spindle-shaped longitudinally, tapering at both ends; 
length = 0.46—0.48 mm, width up to 0.22—0.24 mm across the widest 
part of the spindle. Zooidal boundaries defined by a common, thin, 
raised line of calcification. Cryptocystal surface evenly granular at 
low magnification, the granules looking like small tubercles at higher 
magnification. A shallow, longitudinally crescentic cryptocystal 
ridge occurs on each side frontally between the opesia-orifice and the 
lateral angle of the spindle, these converging but not uniting. The 
cryptocyst most sunken in the vicinity of the opesia-orifice is bean- 
shaped and wider (0.09 mm) than long (0.05—0.06 mm), with a short, 
truncate median convexity in the proximal rim. Orificial denticles or 
condyles not seen owing to occlusion of orifices by sediment in the 
unique specimen. Avicularia and ovicells not seen. 
REMARKS. The unique holotype internode is well preserved but, 
owing to its fragility, broke in two when transferring from an SEM 
stub to the welled slide in which it now resides. The distal end, 
possibly eroded, nevertheless appears to represent a branch locus 
owing to the angles of zooids on opposing faces of the internode. 
Although this species is represented by a single specimen that is 
both infertile and lacks polymorphs, it is named here because of its 
excellent preservation and its distinctively tiny size. Only four 
Tertiary Cellaria species have been reported from New Zealand 
before (Brown 1952). The present material corresponds to none of 
these, nor to any of the approximately 21 species described from the 
Australian Tertiary (see Maplestone 1904; Brown 1958 — note that 
some of the species listed by Maplestone are now recognisable as 
belonging to other cellariid genera), most of which are larger. 
Cellaria perexigua sp. nov. Figs 74, 75 
HOLOTYPE. IGNS BZ 194-1, from Pukekio, Chatham Island. 
PARATYPE. IGNS BZ 194-2. 
NAME. From the Latin, perexiguus, very small. 
