BRYOZOANS FROM CHATHAM ISLAND 
Family LEPRALIELLIDAE Vigneaux, 1949 
Genus INCERTAE SEDIS 
Lepraliellid sp. | Figs 104-106 
IGNS BZ 217, from Pukekio, Chatham Island. 
DESCRIPTION. Colony encrusting. Autozooids porcellanous, 
arranged somewhat irregularly with no discernible boundaries and 
even zooidal orientation is somewhat difficult to determine; length 
ca. 0.43 mm. Frontal shield convex, smooth-surfaced, imperforate 
except for tiny, sparsely distributed pores assumed to communicate 
with areolar septular pores. Peristomial orifice irregular in shape, 
often as wide as long and subrounded, the primary orifice occluded 
and concealed. No oral spine bases. Avicularia sparsely distributed, 
relatively large and more or less lingulate, the broad, rounded 
rostrum slightly broadening distally and with an extensive flat 
palate; there is a relatively large central foramen where the 
avicularium is slightly indented, and a narrow opesial shelf proxi- 
mally; no evidence of a crossbar or distinct mandibular pivots. No 
complete ovicells present, but an excavation distal to one orifice 
appears to represent the inner endooecial surface of a hyperstomial 
ovicell unable to have been closed by the zooidal operculum. 
MATERIAL. 
REMARKS. ‘The generic affinities of the sole specimen are pres- 
ently indeterminable. 
Lepraliellid sp. 2 Figs 109, 110 
MATERIAL. NHM BZ 4788, IGNS BZ 218, two ‘bryoliths’ from 
Pukekio, Chatham Island. 
DESCRIPTION. Colony self-encrusting, multilamellar, forming free 
‘bryoliths’ around a presumed nucleus (a small gastropod shell 
evident in one eroded colony). Autozooids relatively small, arranged 
irregularly, with merging boundaries; length = 0.33—0.37 mm, width 
= 0.28-0.30 mm. Frontal shield convex, more-or-less smooth-sur- 
faced, imperforate except for 8—9 conspicuous areolar pores around 
the margin. Peristomial orifice about as wide as long (both 0.09— 
41 
0.10 mm), the lateral margins continuous with the sides of a median 
suboral avicularium (broken in all zooids), the primary orifice at a 
deeper level and apparently with a straight proximal margin. Distal 
oral spine bases not readily apparent. Chamber of suboral avicularium 
broad, extending to a septular pore on either side. Ovicells not 
identifiable. 
REMARKS. Only the larger of the two colonies is sufficiently well- 
preserved to show details of zooidal morphology. In overall 
appearance the colony and zooids are very typical of celleporids and 
many lepraliellids. The species is not determinable to genus, how- 
ever, and is provisionally included here in the Lepraliellidae on the 
basis of the apparently straight proximal rim of the primary orifice. 
The lack of an orificial sinus suggests that the frontal shield might be 
umbonuloid in structure. 
Family BUFFONELLODIDAE Gordon & d’Hondt, 1997 
Genus CHATAIMULOSIA gen. nov. 
TYPE SPECIES. Chataimulosia primaeva sp. nov., by monotypy; 
latest Teurian-Waipawan (latest Thanetian (earliest Ypresian), 
Chatham Island, New Zealand. 
DIAGNOSIS. Colony encrusting. Autozooids with a smooth, imper- 
forate frontal shield lacking areolar septular pores. Primary orifice 
sunken, the proximal rim straight, lacking a lyrula or denticle. 
Secondary orifice with a median suboral avicularium with crossbar. 
No oral spines. Ovicell hyperstomial, recumbent, smooth and im- 
perforate with its calcification merging into that of the succeeding 
frontal shield. 
NAME. A combination of Chatham and Aimulosia, a genus of 
Buffonellodidae. 
Chataimulosia primaeva sp. nov. Figs 107, 108 
HOLOTYPE. IGNS BZ 202, from Pukekio, Chatham Island. No 
paratypes. 
x 
Figs 109-110 Lepraliellid sp. 2, NHM BZ 4788; 109, zooids visible on abraded colony surface, x 70; 110, secondary orifice and chamber of median 
suboral avicularium, x 300. 
