BRACHIOPODA. 201 



Cyrtina dalmani Meek and Worthen, 1868, 111. Geol. Surv., vol. Ill, p. 383, pi. 7, figs. 



3a, b. 

 Cyrtina dalmani Hall and Clarke, 1893, Pal. N. Y., vol. VIII, pt. II, p. 46. 



Description — "Shell trigonal; valves extremely unequal. Ventral valve triangularly 

 pyramidal. Dorsal valve semi-circular; mesial lobe flat, or with a slightly depressed line; 

 beak scarcely defined, or rising above the hinge line. Hinge line straight. Area tri- 

 angular, flat or slightly arcuate. Foramen narrow, linear, usually closed in the lower 

 part, with a semitubular opening above; concentric labellae strong, and often very con- 

 spicuous near the margin. Surface granulose-punctate." — Hall, 1859. 



Remarks — The observed specimens have 3 or 4 plications on each side of the medial 

 fold and sinus. 



Family Rhynchospiridae 



Genus Rhynchospira Hall 



Rhynchospira formosa Hall 



Plate 52, figures 5-18 



Waldheimia formosa Hall, 1857, 10th Ann. Rept. N. Y. State Cab. Nat. Hist., p. 88. 

 Trematospira formosa Hall, 1859, Pal. N. Y., vol. Ill, p. 215, pi. XXXVI, figs. 2a-i, 



k-p, r-u, 1861. 

 Rhynchospira formosa Hall, 1859, Pal. N. Y., vol. Ill, p. 485, pi. XCVa, figs. 7-11, 1861. 

 Rhynchospira formosa Hall, 1867, Pal. N. Y., vol. IV, pt. I, p. 278, figs. 1-6. 

 Retzia formosa Miller, 1889, N. Am. Geol., Pal., p. 366. 



Retzia formosa Whitfield, 1891, Ann. N. Y. Acad. Sci., vol. V, p. 512, pi. 5, figs. 15, 16. 

 Rhynchospira formosa Hall and Clarke, 1893, Pal. N. Y., vol. VIII, pt. II, p. 109, fig. 



101; pi. L, figs. 21-25, 1894. 

 Retzia formosa Whitfield, 1895, Geol. Ohio, vol. VII, p. 413, pi. I, figs. 15, 16. 

 Rhynchospira formosa Girty, 1899, U. S. Geol. Surv., 19th Ann. Rept., pt. Ill, p. 566. 

 Rhynchospira formosa Weller, 1903, Pal. N. J., vol. Ill, p. 289, pi. XXXI, figs. 9-11. 

 Rhynchospira formosa Clarke, 1908, N. Y. State Mus., Mem. 9, pt. 1, p. 109. 

 Rhynchospira formosa Maynard, 1913, Md. Geol. Surv., L. Dev., p. 246, pi. LXXII, figs. 



26-30. 



Description — "Shell longitudinally ovate. Ventral valve tapering towards the beak; 

 beak prominent rounded, arched or incurved, truncated at the apex by a round perfora- 

 tion, one side of which is formed by the deltidium. Dorsal valve gibbous, sometimes 

 most prominent near the umbo; beak closely incurved beneath the opposite one. Sur- 

 face marked by eighteen to twenty-two or twenty-three simple rounded or rarely sub- 

 angular plications, two or three of which are much smaller and slightly depressed on 

 the middle of each valve, so as to form a faint narrow sinus extending nearly or quite to 

 the apex of the beaks, and giving a slight emarginate outline to the front. Surface 

 marked by fine imbricating concentric lines of growth, which become strong lamellae 

 towards the margins of the shell; shell granulose." — Hall, 1859. 



Remarks — The specimens at hand have from 16 to 23 plications on each valve. 



Genus Trematospira Hall 



Trematospira equistriata Hall and Clarke 



Plate 52, figures 19, 20 



Trematospira equistriata Hall and Clarke, 1894, Pal. N. Y., vol. VIII, pt. II, pi. XLIX, 



fig. 47. 

 Trematospira equistriata Schuchert, 1913, Md. Geol. Surv., L. Dev., p. 430, pi. LXXIII, 



figs. 8, 9. 



