90 
K. L. Prendergast. 
Chapman in 1924 (p. 36), but the specimen has since been re-examined by 
Miss Hosking, and re-identified as Streptorhynchus luiluigui (Hosking 1932^ 
p. 45). 
Linoproductus cora var. foordi (Eth. hi). 
I’l. iii, figs. 3-5. 
1890 . — Froducius temiisiriatus de Verneuil, Foord, p. 151, pi. vii, figs. 4, 4a.. 
1903. — P. te7iuisfriatus de Verneuil, var.. foordi Etheridge, jun., p. 19, pi. i,, 
figs. 3-4; pi. iii, fig. 22. 
1907. — P. tenuistriatus var. foordi Etheridge, jun., p. 30, pi. ix, figs. 4-6. 
1910. — P. tenuistriatus var. foordi Eth. fiL, Glauert, p. 87. 
1931. — P. tenuistriatus var. foordi Eth. fil., Hosking, pp. 8, 22. 
Specimens. — G.S.W.A. 1/4683, south bank of Wooramel River below Cally- 
tharra Spring, Callytharra Limestone. 
G.S.W.A. 5708b., Fossil Cliff, Irwin River. 
Aus. Mus. F 36247, 36251-36255 (inch), Gascoyne River, near Winnemia^ 
North-West Division. Byro Stage. 
Aus. Mus. F 9027, Wyndham River, North-West Division. Byro Stage 
Aus. Mus. F 36287, Gascoyne River, North-West Division. Byro Stage. 
U.W.A. 10822, Fossil Cliff, Irwin River. Fossil Cliff horizon. 
Diagnosis . — Linoproductids with elongate oval outline, hinge-line equal 
to gi’eatest -width of shell. 
Pedicle valve without median sinus. Visceral region very swollen, arch- 
ing over hinge-line, umbo slightly overhanging hinge-line. Ears small and 
hat. Valve regularly curved in longitudinal prohle. Striae hne, irregular,, 
increasing by intercalation along a definite zone. Concentric wrinkles weak,, 
not crossing visceral disc. Groups of spines at cardinal angles and one row 
at low angle to hinge-line. 
Brachial valve concave, ornamentation as in P. cora d’Orbigny. 
Description . — The pedicle valve has an elongated oval outline in the 
larger specimens. It is gibbous in the visceral region falling rapidly at the 
sides to small, flat ears, and truncated posteriorly by a small umbo over- 
hanging the hinge-line. Anteriorly there is a decrease in the curvature so 
that the shell is elongated rather than globular. A row of spines along the- 
hinge, at about 10° to the cardinal margin terminates in a group of from 
4-6 spines on each ear. No spines occur on the rest of the shell. The longi- 
tudinal striae are fine (20-40 measured over a breadth of 20 mm. at a dis- 
tance of 10 mm. from the umbo), and vary in irregularity. On some speci- 
mens they may run almost parallel for the length of the shell, but more 
usually two or more unite and re-divide later, having an irregular course. 
The striae increase by intercalation and this takes place in most specimens,, 
at about the same stage of growth. The amount of increase, too, varies, one 
or two striae being intercalated between a pair of primaries. Folds on the- 
ears are not seen on the majority of specimens and where they are present 
never cross the visceral part of the shell. 
The brachial valve is concave, the ornamentation as in the pedicle valve,, 
but crossed by concentric wrinkles. The valve is devoid of spines. 
