BRACHIOPODA. 203 



Meristella laevis Shimer, 1905, N. Y. State Mus., Bull. 80, p. 255. 

 Meristella laevis Clarke, 1908, N. Y. State Mus., Mem. 9, pt. 1, p. 110. 



Description — "Shell ovate, thin, somewhat ventricose. Ventral valve the larger, 

 most gibbous in the centre and umbonial region, having a shallow mesial sinus extending 

 from the front more than half way to the umbo; beak prominent, ventricose, incurved, 

 not perforate. Dorsal valve regularly convex, gibbous in the middle, but without a 

 defined mesial fold; beak incurved. Surface smooth, or marked by obscure concentric 

 lines and occasional stronger concentric wrinkles of growth, and, in the exfoliated shell, 

 by obscure radiating striae." — Hall, 1859. 



Meristella bella Hall 



Plate 53, figures 3-6 



Merisia bella Hall, 1857, 10th Ann. Rept. N. Y. State Cab. Nat. Hist., p. 92, figs. 1, 3-7. 

 Merista bella Hall, 1859, Pal. N. Y., vol. Ill, p. 248, pi. XL, figs, la-i, k-p, Merisia 



(=Meristella) bella, 1861. 

 Meristella bella Whitfield, 1891, Ann. N. Y. Acad. Sci., vol. V, p. 510, pi. V, figs. 8-10. 

 Menstella bella Hall and Clarke, 1894, Pal. N. Y., vol. VIII, pt. II, pi. XLIII, figs. 



7-9; pi. XLIV, figs. 1-3. 

 Menstella bella Whitfield, 1895, Geol. Ohio, vol. VII, p. 412, pi. I, figs. 8-10. 



Description — "Shell varying from suborbicular or subquadrilateral to transversely 

 oval, usually somewhat broader than long, gibbous. Ventral valve a little the larger, 

 most convex near the umbo ; beak prominent and closely incurved. Dorsal valve convex, 

 gibbous in the middle and towards the umbo; both valves marked with a small sublinear 

 mesial sinus, that of the ventral valve stronger than the other, the two often giving a 

 distinct emarginate outline to the front. Surface smooth, or marked by faint concentric 

 lines of growth, with much fainter indications of radiating striae. 



"[Remarks] * * * * The sinus on the front of the ventral valve is always 

 broader and deeper than that on the other, giving a waved outline to the margins of 

 the valves. * * * ' * * * * * * 



** * # *** * * Hall 1859 



Remarks — But one specimen has been observed. 



Meristella princeps Hall 

 Plate 44, figures 9-11 



Mtrista princeps Hall, 1857, 10th Ann. Rept. N..Y. State Cab. Nat. Hist., p. 95, figs. 



1-5. 

 Merista princeps Hall, 1859, Pal. N. Y., vol. Ill, p. 251, pi. XLIV, figs, la-b, 2a-b, 



3a-c, 4a-h, 5 a-d, Merista (=Meristella ?) princeps, 1861. 

 Camarium princeps Hall, 1859, Pal. N. Y., vol. Ill, p. 486. 

 Meristella princeps Hall, 1860, 13th Ann. Rept. N. Y. State Cab. Nat. Hist., p. 93, figs. 



5-7. 

 Meristella princeps Hall and Clarke, 1894, Pal. N. Y., vol. VIII, pt. II, pi. XLIII, figs. 



10-13. 

 Meristella princeps Shimer, 1905, N. Y. State Mus., Bull. 80, p. 255. 

 Meristella princeps Clarke, 1909, N. Y. State Mus., Mem. 9, pt. 2, p. 41. 



Description— -"Shell ovate; sides sloping towards the beaks at an angle of about 

 60 degrees. Ventral valve more jor less profoundly arcuate longitudinally, most ventri- 

 cose near the central and umbonial region, depressed below and having a broad shallow 

 flat or subangular mesial sinus in front, terminating (in old specimens) in a linguiform 

 extension which is bent upwards at right angles to the longitudinal plane of the shell; 

 beak strongly incurved. Dorsal valve gibbous and extremely elevated along the middle, 

 which becomes in front a strong rounded mesial elevation; sides of the valve declining 



