38 
proximally placed in the frontal shield has been called an ascopore 
(hence Wiesemann’s distinction), but in umbonuloid-shields this 
positional distinction has not the same relevance. 
The presence of spiraminal openings in the Red Bluff Tuff 
specimen is equivocal on the basis of the surficial distribution of 
perforations. Although it was possible to view the proximal part of 
the frontal-shield interior of some zooids at the fractured colony 
edge, amore distally occurring inner spiraminal opening would have 
been missed. Thus the specimen may lack spiramina, in which case 
it could be included in Beisselinopsis. Voigt (1964: 452) describes 
young zooids in the type species, B. hiltermanni Voigt, as ‘perforated 
by a considerable number of pores (?tremopores)’ (see also Voigt 
1962). More and better-preserved specimens from the Red Bluff 
Tuff are needed to settle the matter of generic assignment. Both of 
these genera are otherwise known only in the European Dano- 
Montian. 
The French Paleocene species Beisselina bigeyae Braga & Bignot, 
1986, shows some similarities with ?Pavobeisselina sp. but has 
smaller orifices. 
Family ROMANCHEINIDAE Jullien, 1888 
Genus HIPPOPLEURIFERA Canu & Bassler, 1925 
TYPE SPECIES. Eschara biauriculata Reuss, 1848, by monotypy; 
Badenian (= Langhian (Serravallian), Eisenstadt, Austria (see Hast- 
ings 1966: 73). 
REMARKS. Hippopleurifera is generally included in the family 
Umbonulidae (e.g., Hastings 1949; Bassler 1953; Cheetham 1968; 
David & Pouyet 1974; Schmid 1989); however, the occurrence of 
laterally emplaced avicularia (when present), general appearance of 
the frontal shield, and ovicellular calcification skeletally continuous 
with that of the frontal shield are much more characteristic of the 
closely related family Romancheinidae (cf. the genera Escharoides 
Edwards and Exochella Jullien). 
Hippopleurifera australis sp. nov. Figs 96-99 
HOLOTYPE. IGNS BZ 199, from Pukekio, Chatham Island. No 
paratypes. 
NAME. From the Latin australis, southern, alluding to the first 
occurrence of this genus in the Southern Hemisphere. 
DESCRIPTION. Colony encrusting. Autozooids arranged more-or- 
less quincuncially and as wide as long or longer; length = 0.26—-0.47 
mm, width = 0.46—0.56 mm; the interzooidal boundaries indicated 
by thin irregular suture lines that are difficult to see by light 
microscopy. Frontal shield centrally imperforate with numerous, 
fairly conspicuous areolar pores; these generally in one row around 
the margins but in places encroach 2-3 deep onto the frontal shield. 
Primary orifice sunken, with the distal oral shelf visible at a deeper 
level; secondary orifice generally a little wider (0.15-0.19 mm) 
proximally than distally, the proximal rim concave, gently convex, 
or more or less straight, generally with a spine base visible on each 
side. Secondary orifice cormidial, the distal rim being contributed 
by 1-2 distal zooids whose proximal edges descend to distal rim of 
primary orifice, above which is often a pair of areolar pores. Larger 
pores/foramina in frontal shield, either laterally, proximally, or 
interzooidally, have an inwardly sloping rim surrounding a central 
opesia — these are interpreted to be kenozooids or simple avicularia. 
Ovicells not seen. 
REMARKS. This species accords well with the characters of 
D.P. GORDON AND P.D. TAYLOR 
Hippopleurifera, as exhibited by the range of species attributed to 
this genus. The type species (clarified by Hastings 1966), H. 
biauriculata, has multiple areolar pores that give the frontal shield a 
more porous appearance than in most of the other species in the 
genus, but otherwise shield structure is probably umbonuloid in all 
of them. According to published descriptions, the type species lacks 
oral spines, but these are present in Recent H. pulchra (Manzoni) 
and several fossil species (Hastings 1949; Cheetham 1966). The 
genus is well represented in the European Tertiary, with as many as 
nine species occurring in the Badenian (Langhian-Serravallian) of 
Austria alone (Vavra 1977). The earliest-known occurrence of the 
genus was that of H. canui Cheetham, 1966 from the Lutetian of 
Sussex and southwest France, now antedated by H. australis, which 
is also the first record of the genus from the Southern Hemisphere. 
Genus EXOCHELLA Jullien, 1888 
TYPE SPECIES. 
tralia. 
Mucronella tricuspis Hincks, 1881; Recent, Aus- 
Exochella? gracilis sp. nov. Figs 100, 101 
HOLOTYPE. IGNS BZ 200, a single fragment from Pukekio, 
Chatham Island. 
NAME. From the Latin gracilis, slender, referring to the erect, 
gracile colony form. 
DESCRIPTION. Colony erect, forming gracile, bilamellar stems 
0.80-1.23 mm wide, lensoidal in cross-section. Autozooids alter- 
nate in 2 longitudinal series on each side of the stem, separated by 
another series along each margin; length = 0.64—0.76 mm, width = 
0.35-0.47 mm. Frontal shield increasing in convexity from the 
proximal end towards the orifice, the surface relatively smooth with 
6-7 conspicuous areolar pores along each margin and 1-3 proxi- 
mally. Orifice obscured by sediment, wider (0.18—0.22 mm) than 
long, the proximal rim possibly straight or gently concave. No oral 
spines. In some zooids, one of the midlateral areolar pores is larger 
than the others with an inwardly sloping rim surrounding an oval 
foramen; it appears to be directed outwards laterally and may be an 
avicularium. No ovicells present. 
REMARKS. Owing to occlusion of the orifice by sediment particles 
it is difficult to be certain concerning generic and even familial 
attribution. The presence of a very convex frontal shield suborally 
and an apparent lateral avicularium allows inclusion in the 
Romancheinidae and possibly the genus Exochella (cf. Hayward 
1995: Fig. 137E). More material is needed for confirmation. 
Genus ESCHAROIDES Milne Edwards, 1836 
TYPE SPECIES. 
North Atlantic. 
Cellepora coccinea Abildgaard, 1806; Recent, 
Escharoides? crassa sp. nov. Figs 102, 103 
HOLOTYPE. IGNS BZ 201, from Pukekio Hill, Chatham Island. 
PARATYPE. NHM BZ 4787. 
NAME. From the Latin, crassus, thick, referring to the thick frontal 
shield and peristome. 
DESCRIPTION. Colony encrusting. Autozooids robust, length = 
0.65—0.84 mm, width = 0.50—0.67 mm. Frontal shield thick-walled, 
imperforate except for marginal areolar pores, rising to the broadest 
