LATE TERTIARY POLYCOPID OSTRACODS 
63 
Polycope thomasi sp. nov. 
Figs ID, 2H-I 
Polycope. sp. 2.—Warne 1987: 441. 
Etymology . In recognition of Dr G. A. Thomas, 
palaeontologist. 
Holotype . Adult LV, NMV P122196 from near the top 
of the Fyansford Formation (Middle Miocene, Bal- 
combian) in the south- west face of Batesford Lime¬ 
stone Quarry, near Fyansford, Victoria (base of upper 
quarry bench well above the upper limit of Lepido- 
cyclina sp., approximately 25 m above boundary with 
Batesford Limestone); 38°06'S, 144°17 / E. 
Paratype. Adult RV, NMV PI22197. 
Additional material. Seven disarticulated adult and 
juvenile valves from the Fyansford Formation. 
Dimensions. Holotype, LV, NMV PI22196: L = 0.32 
mm, H = 0.27 mm. Paratype, RV, NMV PI22197: L 
= 0.30 mm, H = 0.26 mm. 
Diagnosis. Carapace very small, subrounded, 
smooth except for faint dorsal and anterodorsal 
ridges adjacent and parallel to outer margin; 
series of rounded opaque (patch) patterns evi¬ 
dent, dense near free margin but sparser in cen¬ 
tral and dorsal regions. 
Description. Carapace thin. LV slightly larger 
than RV and overlapping it dorsally; both valves 
subrounded and produced anterodorsally with a 
distinct rostrum. Dorsal margin slightly arched 
in LV, straight in RV. Maximum length at mid¬ 
height; maximum height anterior of mid-length; 
maximum width at mid-length and slightly 
above mid-height. Surface ornament consisting 
of faint marginal ribs, most numerous antero¬ 
dorsally. Faint peripheral reticulate ornament 
visible, particularly near posterior and ventral 
margins. Carapace almost smooth centrally. 
Normal pore canals simple and scattered. Inner 
lamellae relatively broad with small vestibules 
developed in ventral region of both valves. Mar¬ 
ginal pore canals straight and irregularly spaced. 
Hinge short and adont, thicker terminally than 
in mid-section. Very fine anteroventral denticu- 
lation. Adductors consisting of three sub¬ 
rounded scars in a subtriangular cluster located 
slightly below position of maximum width. 
Sexual dimorphism not detected. 
Remarks. A few specimens have divided pos¬ 
terior and dorsal adductor scars. In these speci¬ 
mens the overall pattern consists of up to six 
individual scars and is reminiscent of that of 
Metapolycope species, though not as complex. P. 
thomasi differs from the other species described 
here in its smaller size. P. denticulata Bonaduce 
et al., 1980 and P. parvula Bonaduce et al., 1980 
are similar to P. thomasi in size but lack the 
marginal ribbing and conspicuous anterior ros¬ 
trum. P. microdispar Hartmann, 1954 is smaller 
than P. thomasi and possesses a narrower inner 
lamellae, whereas P. arenicola Hartmann, 1954 
is larger and slightly more elongate. Eupolycope 
kurilensis (Chavtur, 1977), E. pellucida 
Chavtur, 1979, Polycopetta curva Chavtur, 
1979, Micropolycope angulata (Chavtur, 1977) 
and M. paramushiri (Chavtur, 1977) all resem¬ 
ble P. thomasi in their relatively small size, pre¬ 
sence of an anterior rostrum and relatively 
broad inner lamellae, but have muscle scar pat¬ 
terns consisting of three adductors, except M. 
paramushiri which has a pattern of five scars. 
Age and strati graphical range. Recorded only 
from the early Middle Miocene (Balcombian, 
formaniferal zones N8/9) clays near the top of 
the Fyansford Formation in the Batesford 
Limestone Quarry. 
Polycope warneetensis sp. nov. 
Figs IE, 2J-K 
Polycope. sp. 6.—Warne 1987: 441. 
Etymology. A reference to the type horizon. 
Holotype. Adult LV, NMV PI22198 from the 
“Warneet Sands” (late Late Miocene or Early 
Pliocene, Cheltenhamian or Kalimnan) in the Geolog¬ 
ical Survey of Victoria Sherwood 18 borehole, 
between depths 20 m and 22 m. 38°12'S, 145°16'E. 
Paratype. Adult RV, NMV PI22199. 
Additional material. Nine disarticulated adult and 
juvenile specimens from the type locality. 
Dimensions. Holotype, LV, NMV PI22198: L = 0.55 
mm, H = 0.44 mm. Paratype, RV, NMV P122199: L 
= 0.56 mm, H = 0.46 mm. 
Diagnosis. Carapace of medium size, oval, with 
relatively long dorsal margin, a weakly devel¬ 
oped anterior rostrum in both valves and a faint 
irregular pentagonal network of surface 
furrows. 
