BRYOZOANS FROM CHATHAM ISLAND 
Figs 36-37 Caleschara sp., IGNS BZ 207. 36, autozooids with variably-shaped opesiae, x 33. 37, opesiae and cryptocysts, x 60. 
almost certainly an artifact, especially since oral spines are not 
known in any other species of Calescharidae. The Red Bluff Tuff 
specimen most closely resembles the morphology expressed in 
some populations of Recent C. minuta Maplestone which lack a 
median process of the cryptocyst. Lack of this process is more 
typical of the calescharid genus Tretosina Canu & Bassler, 1927 
which typically has longitudinally elongate-oval opesiae, unlike 
those in Caleschara and the present specimen. 
Family MICROPORIDAE Gray, 1848 
Genus MICROPORA Gray, 1848 
TYPE SPECIES. Flustra coriacea Johnston, 1847, non Esper, 1796, 
by monotypy; Recent, NE Atlantic. 
Micropora quadriporosa sp. nov. Figs 38, 39 
HOLOTYPE. IGNS BZ 186, from Pukekio, Chatham Island. No 
paratypes. 
NAME. Alluding to the number of opesiular pores (four) in the 
zooidal cryptocyst. 
DESCRIPTION. Colony encrusting, tiny, apparently with very short 
pluriserial groupings of zooids. Zooids oval to subpyriform, mostly 
contiguous, but some very slightly disjunct and thus separated by 
distinct interzooidal furrows; length = 0.33—0.45 mm, width = 0.24— 
0.28 mm. Zooids generally with smooth, steeply sloping gymnocystal 
sides and sometimes a short proximal gymnocyst, accentuating the 
appearance of a raised cryptocystal rim. Cryptocyst at a lower level 
than the rim, more or less flat and granular, with 4 circular opesiules; 
one on each side proximal to the orifice, the other pair near the 
proximal end of the cryptocyst. Orifice more or less semicircular, 
but nearly twice as wide as long. No oral spines. Avicularia 
interzooidal, the combined rostral-opesial area somewhat pyriform 
in shape, indented in the middle on each side, possibly lacking a 
complete cross-bar. Ovicell present (broken in the only specimen), 
hyperstomial, evidently not closed by the zooidal operculum in life, 
the outer skeletal surface apparently smooth and imperforate when 
fresh. Basal pore-chambers present in distal half of zooids. 
REMARKS. _ In its range of characters, the genus Micropora is quite 
variable. Species generally have a deep pair of recessed suboral 
opesiules but a few have two to many accessory opesiules (e.g., M. 
variperforata Waters, 1887b; M. gracilis (Uttley, 1949)); most lack 
oral spines, but a few species have them (e.g., Micropora stenostoma 
(Busk, 1854); M. notialis Hayward & Ryland, 1993); avicularia are 
generally present, but are lacking in some species (e.g., M. coriacea 
(Johnston, 1847);M. inarmata Soule, 1959); ovicells are characteris- 
tically imperforate, but M. santacruzana Soule, Soule & Chaney, 
1995 is pseudoporous; how the genus may be split, if this is appro- 
priate, is uncertain, although d’ Hondt & Gordon (1999) have segregated 
as anew genus (Promicroa) a strictly biserial form with pseudoporous 
ovicells and erect dichotomous branches. Because of occlusion of 
avicularian opesiae in the present material it is uncertain whether M. 
quadrispinosa lacks complete cross-bars. If they are lacking, this 
character, the tendency to disjunct zooids separated by deep furrows, 
and especially the hyperstomial ovicell not closed by the zooidal 
operculum, may warrant future segregation at the generic level. 
Genus HOPLITAECHMELLA Voigt, 1949 
TYPE SPECIES. Cellepora vespertilio von Hagenow, 1839, by 
original designation; Upper Senonian, Rtigen, Germany. 
?Hoplitaechmella sp. Figs 40-42 
MATERIAL. IGNS BZ 208, a single colony fragment from Pukekio, 
Chatham Island. 
DESCRIPTION. Colony encrusting. Autozooids arranged quin- 
cuncially; length =0.52—0.60 mm, width =0.43—0.45 mm. Cryptocyst 
granular (preservation of granulation seen proximal to the orifice in 
one zooid). Opesia-orifice wider (0.20-0.24 mm) than long, the 
proximal rim gently concave, with distinct rounded opesiular inden- 
tations at the corners. Oral-spine bases not apparent. As many as 
three small avicularia occur along each lateral margin interzooidally, 
