BRACHIOPODA. 73 



formed. The figures of Merista prunulum, Schnur, from the Eifel, given by 

 QoENSTEDT * indicate that the same feature is also present in this species. It 

 will be conceded that the taxonomic value of this feature is as important as 

 the present basis of distinction between Merista and Meristella, and it is very 

 probable that these Devonian species will afford differences in the structure of 

 the loop.f It will doubtless serve a useful purpose to separate such Devonian 

 species from typical Merista, and the name Dicamara is therefore proposed. 



Genus MERISTELLA, Hall, 1859. 



PLATES XUV, XLV. 



1842. Atrypa, Co.irad.J Joui-nal Acad. Nat. Sci. Philadelphia, vol. viii, p. 265. 



1842. Atrypa, Vasuxkm. Geology of N. Y. ; Kept. Third Dist., p. 120, fig. 2. 



1843. TerebrcUula, Castklxad. Gssai sur le Sjst^me Silurien de I'Amer. Septen., p. 39, pi. xiii, fig. 6. 

 1843. Atrypa, Hall. Geology of N. Y. ; Rept. Fourth Dist., p. 202, fig. 2. 



1857. Merista, Hall. Tenth Rept. N. Y. State Cab. Nat. Hist., p. 92, figs. 1-7 ; p. 94, figs. 1-6 ; p. 95, 



figs. 1-4 ; p. 97. 



1858. Atrypa, Rogers. Geology of Pennsylvania, vol. ii, part ii, p. 825, fig. 642. 



1869. Merista, Hall. Palseontology of N. Y., vol. iii, pp. 247-252, 431, pis. xxxix, xl, xli, xliv, ci, 



fig. 3. 

 1860. Meristella, Hall. Thirteenth Rept. N. Y. State Cab. Nat. Hist., pp. 74, 84, 93, figs. 5-9 ; p. 95, 



figs. 1-5. 



1860. Athyrii1,'Bl\.usr,s. Canadian Journal, [voL v, new ser., p. 279, p. 274, figs. 29-32; p. 281, 



figs. 43, 44. 



1861. Meristella, Hall. Fourteenth Rept. N. Y. Slate Cab. Nat. Hist., p. 100. 



1862. Meristella, Hall. Fifteenth Rept N.Y. State Cab. Nat. Hist., p. 160, figs. 17-22, pi. iii, tigs. 21, 22. 



1863. Meristella, Hall. Sixteenth Rept. N. Y. State Cab. Nat. Hist., p. 50, figs. 27-34. 

 1863. Meristella, Hall. Ameiican Journal of Science, vol. xxxv, p. 396; vol. xxxvi, p. 11. 

 1863. Meristella, Hall. Transactions of the Albany Institute, vol. iv, pp. 139, 140. 



1863. Athyris, Billinos. Ptoc. Portland Soc. Nat. Hist., vol. i, pp. 115, 116, pi. iii, figs. 13, 14. 



1863. Charlonella, Billinos. Geology of Canada, p. 373, tig. 397; p. 374, figs. 400e, 401; p. 385, tig. 420. 



1866. Merista,' S.. Wischell. Geol. Rept. of the Lower Peninsula of Michigan, p. 94. 



1867. Meristella, Hall. Palseontology of N. Y., vol. iv, pp. 295-299, 303-308, 420, plates xlviii, xlix, 1, 



figs. 1-17; Ixiii, figs. 15-22. 



1868. Merista, Mukk and Woktuks. Geological Survey of Illinois, vol. iii, p. 376, pi. vii, fig. 8. 

 1874. Athyris, Nicholson. Palaeontology of the Province of Ontario, p. 86. 



1874. Athyris, Billings. Canadian Naturalist and Geologist, vol. vii, new ser., p. 240. 



1884. Meristella ( Whitfieldia), Walcott. Monogr. U. S. Geol. Survey, vol. viii, p. 148, pi. iii, fig. 8. 



1889. Meristella, Nbttblboth. Kentucky Fossil Shells, pp. 97, 98, pi. xv, figs. 2-8. 



1889. Meristella, Simpson. Transactions of the American Philosophical Society, vol. xvi, p. 442, fig. 7. 



* Petrefactenkunde Deutscblands ; Brachiopoden, pi. 11, tigs. 69-75. 1871. 



t Dr. Davidson i-efers to jireparations of Merista prunulum by Zogmayer, and implies that there are 

 some minor differences in the loop, etc., from these atructui-es in M. herculea. Dr. Zdgmaybb's observations 

 have not been published, and therefore we can venture no opinion as to how far such differences as he may 

 have discovered will fortify the distinction above indicated between the Silurian and Devonian species cur- 

 rently refen-ed to Mbbista. 



