Bd. III: 7) 
ANTARCTIC FOSSIL BRACIIIOPODA. 
29 
Description: ‘Shell small, broadly oval, a very little longer than wide. Brachial 
valve regularly convex deeper than the peduncular valve, which is moderately con- 
vex and slightly impressed in the middle line towards the front. Surface orna- 
mented with numerous rounded, bifurcating radial ribs, crowded towards the front, 
and with imbricating concentric lines of growth towards the same region. Beak 
stout, obtuse; hinge line narrow, slightly arched; fissure large, deltidial pieces incon- 
spicuous.’ 
Remarks: The above is Tate’s description, and allowing for size the large 
Antarctic specimen agrees very closely with it. The chief différences are those that 
would belong to larger growth: thus it is elliptical, and a good bit longer than 
wide; but the growth lines show that there was complete agreement with Tate’s 
description at the same size. Near the beak the ribs increase by intercalation; later 
by bifurcation most frequently, but there is some intercalation. 
‘Hinge line narrow, slightly arched’ is difficult to understand. The true hinge 
line shown by the dorsal (brachial) valve is short, and obtusely angulate; it extends 
to about the edge of the deltidial plates. Beyond that the line of valve junction 
falls off at a less angle. 
The discrepancies with Tate’s figures and descriptions are: that the beak area 
is larger; this may be due to age; that the slight ventral sulcus shown in Tate’s 
fig. 4 c is greater than in the ‘large Antarctic specimen, PI. Ill, fig. 4 b, whereas 
according to age it should be more pronounced in the present shell: as a matter 
of fact there is only a slight, hardly noticeable ventral depression. 
The agreements are so numerous, and the available material so scanty that it 
is only justifiable at present to inscribe the Antarctic specimens with Tate’s name. 
Locality: Cockburn Island (13), Graham Land, Antarctica. 
Formation: Glauconitic Bank. 
Material: One example, probably full grown; and one small specimen. The 
large example is in excellent preservation. 
Other localities: ‘Abundant in the glauconitic limestones, north of Blanche Point, 
Aldinga Cliffs, and in the yellow clays at Muloowurtie, Yorke’s Peninsula’ (Tate, 
p. 161). 
Terebratulina oamarutica, Boehm? 
PI. Ill, fig. 5 - 
1904. Terebratulina oamarutica^ Boehm, Brach. Neu-Seeland, p. 148, PI. XV, figs, i — 5. 
Remarks: One quite small specimen more coarsely ribbed than Tcrebratnli)ia 
letiticularis^ Tate, is not unlike the species figured by Boehm. It has, however, a 
straighter lateral margin and a less gibbous ventral valve. 
