Permian Productinae and Strophalosiinae of W.A. 
47 
Internally the adductor impressions are seen high up in the valve; they 
<^l•e separated medially by a narrow groove. Longitudinal striations mark 
the shell at the side of the adductor impressions and are probably the im- 
pressions of the diductor muscles. 
Comparison ivith other species. — This specimen has been referred to 
Strophalosia gerardi rather than identified with it. The general outline of 
the Irwin River shell is much broader than any specimen of Sir. gerardi, and 
the spines are more widely spaced and less oblique than in that species. This 
.specimen is possibly a local variant of Str. gerardi^ but in the absence of 
intermediate forms cannot be satisfactorily united with it. 
Strophalosia jukesi Eth. fil. 
P1..V, figs. 18-20. 
f8S0. — Strophalosia jukesi Etli. fil., p. 307, pi. xiii, figs. 39-43. 
1888. — Strophalosia jukesi Eth. fil., Jolmstoii, pi. xiv, fig, 7. 
Si/ntypes. — R.M. 96874, 96931. New South Wales. Exact locality and hori- 
zon unknown. Figured by Etheridge 1880, pi. xiii, figs 39-43. 
Other Material. — Commonwealth Palaeontologists^ Coll. P. 14. Talbot’s 
<7011-11, Woorainel River District. U.W.A., 20264. same locality and horizon. 
U.W.A., 20266, same locality and liorizon. 
Diagnosis. — Shell elongate-oval in outline, hinge-line less than maximum 
shell width. Ornamentation of spines and concentric lamellae on both valves. 
Pedicle valve evenly convex with flattening towards anterior margin 
and steo]) slope to cardinal margin. Area wide and distinct, pseudo-deltidium 
triangular. Ears small. Cardinal angles obtuse. Muscles high in valve, 
adductors central and compact, diductors tlabeliate and longitudinally striate. 
Brachial valve concave, greatest concavity in front of umbo. Area 
distinct, half as wide as area of ]:)edicle valve. Adductor muscle impressions 
divided into anterior and posterior sections. Cardinal process large, trifid, 
continuing into strong median septum. 
Description. — A number of ferruginous casts have been referred to this 
species, as they agree in all particulars with Tasmanian specimens. For a 
<-:omplete descri])tion of the species see Prendergast (Proc, Rog. Soc. Tas- 
mania).* 
Strophalosia kimberleyensis n. sp. 
PI. vi, figs. 1-5. 
1890. — Strophalosia cJarkei Etheridge, Foord, p. 103, pi. v, fig. 7-8, text-fig. 6. 
1903. — Strophalosia sp. ind, Etheridge, .inu., p. 20, pi. i. figs. 10-12. 
llolotype. — F.W.A. 20452 north of Hill C, south side of Grant Range, Kim- 
berley Division. F])])cr Ferruginous Series. 
Paratypes. — T'.W.A. 20460, same localitv and horizon. 
ir.W.A. 2045.5, Nooncanbah Homestead, Kimberley Division. Nooneanbah 
Series. 
Topotype.s.—V.\\\A. R 127. 
Other Material.— P>.M. B 4590, 4591, south-east of Mt. Abbott, on Fitzvoy 
River, Kimberley Division. Horizon unknown. (Figured by Foord 1890). W.A. 
Mus. F 166 (47441, Cookilya Pool, Wandagee Station. Minilva River. Wandagee 
stage. (Figured by Etheridge, 1903). W.A. Mus. a 12, south-east of Mt. 
Abbott, Fitzroy River, Kimberley Division. Horizon unknown. Aus. AIus. F 
37523-37529; IMinilya River. Wandagee stage. Aus. Mus. F 36221-36225, Jimba 
Jiml)a Station, Gaseoyiie River. Byro stage. U.W.A. 13. 51. Nooncanbah Home- 
stead, Kimberley Division. Nooncanbah series. 
Diagnosis. — Shell sub(]uadrate to ovate in outline, pedicle valve inflated 
to bemisi)herieal. braehial valve evenly concave, liinge line almost greatest 
width of shell. 
