AUSTRALASIAN TERTIARY BRACHIOPODA 
39 
Fig. 4. A-F, Elderra toorlooensis sp. nov. A, paratype NMV PI 7352, dorsal interior, x 2.6. B-E, holotype NMV 
PI 7351, dorsal, ventral, lateral and anterior (ventral valve uppermost) views, x 1.25. F, paratype NMV PI 7353, 
ventral interior x 1.7. 
Comments. The heavily thickened hinge plat¬ 
forms of the two species included in Adnatida 
appear to contain no sites for muscle attachment 
other than the posterior surface of the cardinal 
process (attachment surface of the diductor 
muscles). The absence of a hinge trough or pits, 
together with the small erect beak and tiny fora¬ 
men. are indicators of an atrophied pedicle 
system and a free-lying existence. The appear¬ 
ance of the hinge platform suggests that a life¬ 
style characteristic of species of Anakinetica 
would have preceded loss of pedicle function in 
the species of Adnatida. 
The species of Adnatida may be differentiated 
externally by the curvature of the cardinal mar¬ 
gin (moderate in A. deformis , strong in A. gnan- 
garensis ), degree of sulcation (moderate in A. 
gnangarensis , strong in A. deformis ), shape 
(broadly ovate in A. deformis , pyriform in A . 
gnangarensis) and in the pronounced convexity 
of the dorsal valve of A.deformis. The loop of 
neither species has been preserved, but the con¬ 
dition of the septum suggests that the loop of A. 
deformis would show ascending and descending 
branches, whereas that of A. gnangarensis would 
have fused branches with thin, lateral connect¬ 
ing bands. 
Adnatida deformis (Tate, 1880) 
Fig. 5G-K 
Magasella deformis Tate 1880: 165-166, pi. 10, fig. 
5a-c. 
Magadinaf?) deformis. —Thomson 1927: 267. 
Type material. Five syntypes, SAM T888A-E, from 
the Tortachilla Limestone (Eocene), Maslin Bay, Al- 
dinga, South Australia. 
Description. Length of figured specimen (Fig. 
5H-K) 11.7 mm, breadth 9.2 mm, depth 6.6 
mm. Strongly sulcate. Outline broadly ovate, 
greatest width just anterior to mid-length. 
Symphytium slightly concave; cardinal margin 
slightly curved. Hinge platform almost circular 
in outline; posterior surface of cardinal process 
roughened, slightly lower than surrounding plat- 
