312 
R.S. Craig 
|-W, -t : 
W, 
«— w 4 -► 
Figure 1 A, Sketch of ventral valve interior and 
measurement parameters of Westralicrania 
zenobiae: L,, maximum valve length; L 2 , 
length from posterior margin to anterior of 
median septum; L., length from posterior 
margin of limbus to anterior of median 
septum; L v length of posterior muscle scar; 
L„ length of median septum; W, maximum 
valve width; W,, width from inside limbus to 
median septum; VJ y width of lateral limbus. 
B, Sketch of ventral valve exterior and 
measurement parameters of VV eslralicrania 
zenobiae: L 6 , length of exterior flattened 
attachment area; W ( , width of exterior 
flattened attachment area. 
posterior muscle scars in Westralicrania are raised 
on platforms and without pits. In Danocrania the 
muscle scars occur in pits and not on platforms. 
Westralicrania is therefore regarded as a valid 
genus. 
Westralicrania zenobiae sp. nov. 
Figures 1,2 
Diagnosis 
Relatively large species of Westralicrania. Exterior 
valve with radiating short spines arranged in lines. 
Interior posterior muscle scars large; median 
septum short; pseudointerarea large and anacline. 
Etymology 
The species is named in honour of my wife, 
Zenobia. In Greek, Zenobia means "her father's 
jewel". 
Material examined 
Holotype WAM 94.29, ventral valve from the 
Nanarup Limestone (Late Eocene), Nanarup Lime 
Quarry. Paratypes WAM 94.30 to 94.40, ventral 
valves from the same horizon and locality as the 
holotype. 
Other material 
WAM 94.41, a ventral valve from the Nanarup 
Limestone, near Manypeaks Homestead. WAM 
94.28 and WAM 88.373, dorsal valves from the 
Toolinna Limestone, Israelite Bay. 
Description 
Ventral valve 
Shell reaches a maximum known length of 11.7 
mm (Table 1); triangular to pear shaped (Figure 
2A-I), width 80% of shell length (SL); dorso- 
ventrally flattened. Growth lines on exterior 
indicate mixoperipheral growth, pronounced 
growth lines on the pseudointerarea. Exterior has 
elongated pustules to spines which radiate in lines 
from the posterior attachment area behind the 
pseudointerarea with some intercalation (3 per 
mm). The spines themselves point in a posterior to 
anterior direction. Attachment area is a distinct 
elliptical region of flattening (16% SL, 22% shell 
width [SW]). Because pseudointerarea is slightly 
anacline, shell is raised from attachment area. The 
triangular pseudointerarea (31% SL) bears definite 
stepped growth lines, 3 in the smallest to 11 in the 
largest. A flat limbus entirely surrounds concave 
depression of shell interior. Posteromedian 
extension of limbus impinges slightly on 
depression before it drops to a shallow depression 
between large paired, raised muscle scars (20% SL). 
Traced anteriorly, this depression leads to a small 
median septum or ridge (13% SL) with raised 
anterior muscle scars on each side with single 
depression in each. Interior of shell is 
endopunctate, which in the smallest specimen, 
leads to shell appearing as if it is tuberculate. 
Endopunctae radiate from posterior margin in 
front of pseudointerarea. Limbus and posterior 
