Permian Productinae and Strophalosiinae or W.A. 
31 
1861. — Froductus spinulosus J. Sowerby, Davidson, vol. ii, part 5, No. 4, 
p. 175, pi. xxxiv, figs. 18-21. 
1914. — Pusttila spmulosa J. Sowerby, Thomas, p. 314, pi. xviii, figs. 7-9; 
pi. xix, figs. 7, 8. 
1930. — Krotovia spinulosa (Martin), Muir-Wood, p. 106. (There is no Pro- 
ductus spinulosus Martin — this is a mistake in author of species) . 
Jloloiype. — Present location unknown, listed as Royal Scottish Museum, 
Edinburgh, Pleming Collection. Carboniferous Limestone, West Lothian, Lin- 
lithgowshire. 
Material. — Aus. Mus. E 38442, 38443, 38446, Wandagee Station, Minilya 
River, North-West Division. Wandagee Stage. 
Aus. Mus. F 37563, 37564, 37578, 37582, bank of Minilya River, North-West 
Division. Wandagee Stage. 
Aus. Mus. F 37725. 
Aus. Mus. F 37579, ni. west of shale outcrop, northern bank of Minilya 
River, North-West Division. Wandagee Stage. 
Diagnosis. — Shell small. Outline oval, hinge-line less than maximum 
width. Pedicle valve convex, non-sinuate, umbo small, pointed and incurved, 
overhanging hinge-line; ears small and flat. Brachial valve evenly concave. 
Visceral cavity of Productus typici jS type. Ornamentation on both valves 
of fine oblique spines, closely spaced, with quincuncial arrangement. De- 
velopment of incipient costae below spines near anterior margin. 
Internal features not known. 
Dimensions. 
Description. 
Type. 
F 38443 
F 38446 
Height 
16.2 
16.5 
Length of hinge line 
10.5+ 
12.5 
Maximum width 
11.7+ 
17.3 
Curvilinear length of pedicle valve 
29.4 
27.4 
The shells of this species, as may be 
seen from 
the table. 
are small. 
Usually transversely oval, they have a straight hinge-line shorter in length 
than the maximum width of the shell. 
The pedicle valve is evenly convex, without a median sinus. The shell 
has its maximum convexity behind the umbo; from this point the sides drop 
steeply to fiat ears; anteriorly the slope is more gradual. The alar angles are 
obtuse. The umbo is small, pointed and overhanging the hinge-line. The 
surface of the valve is ornamented by small closely-set spine bases (10-12 in 
10 mm. at a distance of 10 mm. from the irnibo). These give rise to slender 
oblique spines on the body of the shell; they have not been observed on the 
ears, but a row of erect spines separates the ears from the body of the shell. 
On the anterior and lateral slopes small ripples ( ? incipient plications) are 
seen anterior to the spine bases. 
The brachial valve is regularly concave with the maximum concavity 
just beneath the umbo. The ears are flat and in contact with those of the 
pedicle valve. The ornamentation is the same as that seen on the pedicle 
valve, but no spines are preserved on the brachial valves. A few growth lines, 
cross the shell. 
Comparison with other species. — Productus opuntia Waagen resembles 
this species in many particulars. Both have the same outline, but may be dis- 
tinguished by the location of the maximum width which in P. opuntia is the 
length of the hinge-line. The spine bases of P. opuntia are not so crowded as 
those of P. spinulosus and generally are more robust, having a distinct an- 
terior prolongation and are also more nodular. 
