188 THE DEVONIAN OF MISSOURI. 



Description — "Shell semi-elliptical, width nearly one-half the length, plano-convex; 

 hinge line greater than the width of the shell below; the cardinal extremities often salient. 

 Dorsal valve flat. Ventral valve uniformly and very slightly convex, sometimes flat- 

 tened towards the margins; beak scarcely elevated above the hinge line. Area linear. 

 Foramen unknown. Surface finely and evenly striated; striae of the dorsal valve often 

 flattened. Radiating striae crossed by fine closely arranged concentric striae, and some- 

 times with a few inconspicuous laminae of growth, and towards the cardinal extremities 

 by a few wrinkles or undulations. 



"{Remarks] * * * The striae are fine, equal or subequal, gently undulating, 

 and increasing both by bifurcation and interstitial addition. A very slight exfoliation 

 obliterates the concentric striae. The surface, when very slightly weathered, presents 

 numerous punctures arranged in lines parallel with the striae; and these punctures are 

 often visible upon the fresh unworn surface * * * 



—Hall, 1859. 

 Genus Strophoneiia Hall 



Strophonella punctulifera (Conrad) 



Plate 47, figures 3-6 



Leaptaena punctulifera Conrad, 1838, 2nd Rept. N. Y. Geol. Surv., pp. 112, 117. 

 Strophomena punctulifera Vanuxem, 1842, Geol. N. Y., Rept. 3rd Dist., p. 122, fig. 5. 

 Strophomena (Strophodonta) punctulifera Hall, 1857, 10th Ann. Rept. N. Y. State Cab. 



Nat. Hist., p. 50, fig. 1. 

 Strophodonta cavumbona Hall, 1857, 10th Ann. Rept. N. Y. State Cab. Nat. Hist., p. 51. 

 Strophomena punctulifera Rogers, 1858, Geol. Penn., vol. II, pt. II, p. 825, fig. 648. 

 Strophodonta punctulifera Hall, 1859, Pal. N. Y., vol. Ill, p. 188, pi. XXI, figs. 4a, b;, 



pi. XXIII, figs. 4 a-c, 5c, 7e, 1861. 

 Strophodonta cavumbona Hall, 1859, Pal. N. Y., vol. 'III. pi. 187, pi. XXI, figs. 1-3, 



1861. 

 Strophomena punctulifera Billings, 1863, Proc. Portland Soc. Nat. Hist., p. 108, pi. 3, 



fig. 2. 

 Strophomena punctuhfera Billings, 1863, Geol. Canada, p. 957, fig. 448. 

 Strophomena punctulifera Billings, 1874, Pal. Fossils, vol. II, p. 31, pi. 3, fig. 2. 

 Sttophonella punctulifera Hall, 1879, 28th Ann. Rept. N. Y. State Mus. Nat. Hist., p. 



154. 

 Strophonella punctulifera Hall, 1883, Rept. State Geol. N. Y. for 1882, pi. XLIII, figs. 



10-12. 

 Strophodonta punctulifera Walcott, 1884, U. S. Geol. Surv., Mon. VIII, p. 121, pi. 13, 



fig. 10. 

 Strophonella punctulifera Hall and Clarke, 1892, Pal. N. Y., vol. VIII, pt. I, p. 292, 



pi. XII, figs. 10-12. 

 Strophonella cavumbona Hall and Clarke, 1892, Pal. N. Y., vol. VIII, pt. I, pp. 291, 292. 

 Strophonella punctulifera Weller, 1903, Pal. N. J., vol. Ill, pp. 277, 301, pi. XXVII, 



figs. 6-8; pi. XXXIII, fig. 9. 

 Strophonella punctulifera Shimer, 1905, N. Y. State Mus., Bull. 80, p. 242. 

 Strophonella punctulifera Clarke, 1908, N. Y. State Mus., Mem. 9, pt. 1, p. Ill, pi. 37, 



figs. 10, 11. 

 Strophonella punctulifera Clarke, 1909, N. Y. State Mus., Mem. 9, pt. 2, p. 45, pi. 9, 



figs. 16-18. 

 Strophonella punctulifera Schuchert, 1913, Md. Geol. Surv., L. Dev., p. 323, pi. LIX, 



figs. 8-10. 



Description — "Shell subsemicircular, about four-fifths as long as wide. Ventral 

 valve concave; beak not projecting beyond the hinge. Dorsal valve concave near the 

 umbo, very convex near the middle; beak not elevated above the cardinal margin; 

 sides somewhat contracted below the extremities of the hinge. Hinge line straight, nearly 



