42 
Producius semireticulatus (Martin) 
1809. Anomites semireticulatus Martin, Petrifacta Derbiensia, p. 7, PI. 32, 
figs. 1, 2, PI. 33, fig. 4; Producius semireticulatus Meek, 1872, Final 
Kept. U.S. Geol. Surv., Nebraska, p. 166, PL 5, figs. 7a, b; White, 
1876, Wheeler's Expl. Surv. W. 100th Mer., vol. 4, p. Ill, PL 8, 
fig. 1; Meek, 1877, King's U.S. Geol. Expl. 40th Par., vol. 4, p. 
69, Pl. 7, fig. 5; White, 1884, 13th Kept. State Geol. Indiana, p. 125, 
Pl. 24, figs. 1-3; Hall and Clarke, 1892, Pal. N.Y., vol. 8, pt. 1, Pl. 
17A, figs. 16-18, Pl. 18, figs. 11-13, PL 19, figs. 19-23; Keyes, 1895, 
Geol. Surv., Missouri, p. 50, Pl. 36, fig. 4. 
Above are cited a few references to the Pennsylvanian occurrence of 
this species. The species is less widely cited from the Mississippian. 
Remarks . The very poorly preserved specimens identified with this 
species are large, moderately convex pedicle valves, wider than long, with a 
broad, rather weakly developed median sinus from which the surface 
rounds abruptly and then gently descends to the lateral margins. A 
transverse section thus does not at all give a quadrate outline. Hinge-line 
almost as long as the width of the shell in front. Surface covered with 
coarse radiating costse, from three to four occupying the space of 5 mm. 
Strong concentric wrinkles cover the umbonal region. Two brachial 
valves with a shallow median fold and with surface characters similar to 
those of the above pedicle valves probably belong to this species. 
Locality and Horizon. Throughout the Pennsylvanian of North 
America, rarer in the Permian. In the Minnewanka region in the Permian 
of section 1-14 (c); in the Pennsylvanian of section 2-1 (?). 
Producius coloradoensis Girty ? 
1903. Productus inflatus Girty (non McChesney), U.S. Geol. Surv., Prof. 
Paper 16, p. 359, Pl. 3, figs. 1-3; Girty (non McChesney), 1904, 
U.S. Geol. Surv., Prof. Paper 21, p. 52, Pl. 11, figs. 5, 6; Productus 
inflatus var. coloradoensis Girty, 1910, N.Y. Acad. Sci., Annals, 
vol. 20; Girty, ? 1911, U.S. Geol. Surv., Bull. 439, p. 42, Pl. 4, 
fig. 3; Girty, ? 1915, U.S. Geol. Surv., Bull. 593, p. 47, PL 3, figs. 
7-8 a. 
Remarks . The Minnewanka form is quite similar to the one figured 
and described by Girty under this name. The specimens are poorly pre- 
served; otherwise a more exact determination could be made. Our form 
is apparently somewhat nearer P. coloradoensis than to P. hermosanus 
Girty from the Pennsylvanian of Colorado. The latter very closely re- 
lated species is proportionately somewhat broader with somewhat coarser 
cost®. The row of spines at the base of the ears, also shown upon the 
figures of this type, allies this shell with P. costatus and distinguishes it 
from the Mississippian P. fernglenensis and P. burlingtonensis. 
Locality and Horizon. In the Pennsylvanian of Arkansas, Colorado, 
and Arizona. Ip the Minnewanka region in the Permian of section 1-14 
(r); in the Pennsylvanian of section 2-11 (c), 13 (C), 14 (r). 
