32 
D.P. GORDON AND P.D. TAYLOR 
Figs 79-81 Cellaria cf. depressa Maplestone, 1900, IGNS BZ 212. 79, internode, x 50. 80, occluded autozooidal orifice and adjacent ?avicularium 
(lower right), x 210. 81, orifice and cavity of an ovicell, x 160. 
DESCRIPTION. Colony erect, comprising proximally tapered, nar- 
row bilamellar stems that periodically produce narrower side 
branches. The larger colony fragment is 1.60-3.00 mm wide, 
lensoidal in cross section, with side branches ca. 1.49-1.61 mm 
wide. Zooids regularly alternating such that opesia-orifices occur in 
straight oblique rows, interzooidal boundaries not clearly discern- 
ible; length = 0.52—0.75 mm, width = ca. 0.32 mm; cryptocyst 
depressed, sloping inwards to the external opesia-orifice which is 
more-or less D-shaped, 0.14—0.19 mm wide; primary orifice sunken, 
the proximal rim shallowly concave with narrow but distinct opesiular 
indentations at the corners. Avicularia not seen. Ovicells in the 
present worn material broken, indicated by relatively deep cavities, 
each immediately distal to the opesia-orifice and separated from it 
by the distal rim of the maternal zooid; these cavities almost twice 
the height (length) of the subjacent opesia-orifice. 
REMARKS. The specimens of this bryozoan are not well-enough 
preserved to name as a new species, especially as some morphologi- 
cal characters are lacking, but the colony form is distinctive enough 
to allow recognition should additional material be found. It shares 
some of the attributes of erect bilamellar forms of Aspidostoma but 
the unequal mode of branching (not regular bifurcations) and form 
of the orifice are more suggestive of cellariid affinity. 
Genus MELYCHOCELLA gen. nov. 
TYPE SPECIES. Melychocella cynura sp. nov. 
DIAGNOSIS. Colony erect, bilamellar, with somewhat hexagonal 
zooids arranged in continuous longitudinal series. Cryptocyst sunken, 
no ridges, the opesia-orifice wider than long with both proximal and 
distal condyles and small opesiular indentations. Scattered vicarious 
avicularia have rostral and opesial foramina. Ovicells large, the 
frontal surface not crossed by the outer angles of adjacent zooids. 
NAME. The name is a composite of Melicerita and Onychocella, 
alluding to the combination of morphological characters of these 
genera. 
Melychocella cynura sp. nov. Figs 88-92 
HOLOTYPE. IGNS BZ 197-1, from Pukekio, Chatham Island. 
PARATYPES. IGNS BZ 197-2, 197-3, 197-4. NHM BZ 4786. 
NAME. Cynura is a latinisation of the Greek kynouron, a sea-cliff, 
alluding to the type locality. 
DESCRIPTION. Colony erect, bilamellar, 0.72—0.75 mm thick. 
Autozooids alternating, nearly hexagonal, averaging a little longer 
than wide (length = 0.44—0.56 mm, width = 0.37—0.52 mm) and 
clearly defined by the raised lateral margins, the longitudinal series 
continuous, not discontinuous. Cryptocyst completely sunken with 
no ridges, the surface distinctly granular. Opesia-orifice relatively 
large, wider (0.20—0.24 mm) than long (0.10—0.12 mm, as measured 
from middle to middle of each rim), with the corners extended a little 
proximally as rounded opesiular indentations, each being adjacent 
