Permian Productinae and Strophalosiinae of W.A. 
23 
The sizes of the specimens (pedicle valves) are shown by the following 
table : — 
1 . 
2. 
3. 
4. 
5. 
6. 
Height 
29-1-f 
22-8-h 
31-0 + 
23-7 + 
23-04- 
14-1 
Maximum width 
29-4 + 
25- 1-h 
27-0-f 
27-04- 
24-0 + 
13-3 
Length of hinge- 
line 
22-9 + 
20'2-y 
19-84- 
25-0 
18-6 + 
13-3 
Curvilinear length 
50-0-1- 
39-3-h 
56-0 + 
41-14- 
35-5-f 
21-8 
No specimens examined have both valves in position, it is thus impossible to 
estimate the thickness of the shell. 
The width of the hinge-line as shown by these figures is less than the 
maximum width of the shell. The ears in these specimens are very fragile 
.and readily break off; the only complete specimen is a small one (No. 6). 
The internal structures are as described for the species P. cora^ the 
muscles being inserted in definite fossae. 
Comparison with other forms. — These specimens have been referred for 
many years to Prodiictus temiistriatus Verneuil, although distinguished as a 
variety. Etheridge (1903) separated them as a variety giving as his reasons 
the much coarser and more irregular ornamentation (in P. temiistriatus there 
are 50-60 striae in 20 mm. at a distance of 20 mm. from the umbo). They 
differ from that species, too, in the width of the hinge-line, the arching of 
the i)edicle valve and the regular anterior elongation, P. tenuistriatus being 
irregularly produced anteriorly. Etheridge has already said that this form 
belonged to the ^^cora’^ group (1907, p. 30). Specimens from Timor (Broili 
1916, pi. cxv., figs. 15-16; pi. cxvi., figs. 1-3) probably belong to this variety 
‘Oi P. eora. 
This variety is not distinct from P. cora d’Orbigny. It is a variety 
within that species as can be seen by a comparison of KozlowskPs figures 
(pi. vi., figs. 7a, b) and figures accompanying this paper, but a variety which 
has become stabilised in this area. The limits of variation are narrower than 
in those from South America. The shell shape is constant as is the convexity 
■of the pedicle vaNe, it is not sinuated and does not carry spines on the main 
part of the shell. The varietal name is retained for these specimens until 
the complete range of Productus cora d’Orbigny is seen in this country. 
Linoproductus cancriniformis (Tschernyschew). 
1889. — P. cancriniformis Tschernyschew, p. 373, p]. vii, figs. 32, 33. 
1897. — P. cancriniformis Tsehern. Diener, vol. 1, Pt. Ill, p. 25, pi. vi, figs, 
fia-b, 7a-d. 
1897. — P. cancriniformis Tsehern. Diener, vol. 1, Pt. TV, p. 31, pi. 1, figs. 
1907. — ^‘P, nndatus^^ Def ranee, Eth. fil., p. 30. 
1916.- — P. cancriniformis Tsehern., Broili, p. 13, pi. cxvi, fig. 6. 
1918. — ‘^P. hellns’^ Eth. fil., p. 254, pi. xxxix, fig. 4-5; pi. xl, fig. 6. 
1928. — L. cancriniformis (Tsehern.), Chao, p. 65, pi. v, figs. 8-9. 
1934. — L. cancriniformis (Tsehern.), Prendergast, p. 14, pi. ii, figs. 7-12. 
1936. — L. ca7ieriniformis (Tsehern.), Douglas, p. 30, pi. iv, fig. 3. 
