BRACHIOPODA. 
73 
formed. The figures of Merista prunulum, Schnur, from the Eifel, given by 
Quenstedt,* 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. 
1842. 
1842. 
1843. 
1843. 
1857. 
1858. 
1859. 
1860. 
1860. 
1861. 
1862. 
1863. 
1863. 
1863. 
1863. 
1863. 
1866. 
1867. 
1868. 
1874. 
1874. 
1884. 
1889. 
1889. 
Genus MERISTELLA, Hall. 1859. 
S PLATES XLIVJXLV. 
Att'y'pa, Conrad. J [Journal Acad. Nat. Sci. Philadelphia, vol. viii, p. 265. 
Atrypa, Vanuxbm. Geology of N. Y.; Kept. Third Dist., j). 120, fig. 2. 
Terehratula, Castelnau. Essai sur le Systeme Silurien de I’Amei’. Septen., p. 39, pi. xiii, fig. 6. 
Atrypa, Hall. Geology of N. Y. ; Kept. Fourth Dist., p. 202, fig. 2. 
Me^'ista, Hall. Tenth Kept. N. Y. State Cab. Nat. Hist., p. 92, figs. 1-7 ; p. 94, figs. 1-6 ; p. 95, 
figs. 1-4 ; p. 97. 
Atrypa, Rogers. Geology of Pennsylvania, vol. ii, part ii, p. 825, fig. 642. 
Merista, Hall. Palaeontology of N. Y., vol. iii, pp. 247-252, 431, pis. xxxix, xl, xli, xliv, ci, 
fig. 3. 
Meristella, Hall. Thirteenth Kept. N. Y. State Cab. Nat. Hist., pp. 74, 84, 93, figs. 5-9; p. 95, 
figs. 1-5. 
.?, Billings. Canadian Journal, [vol. v, new ser., p. 279, p. 274, figs. 29-32; p. 281, 
figs. 43, 44. 
Meristella, Hall. Fourteenth Kept. N. Y. State Cab. Nat. Hist., p. 100. 
Meristella, Hall. Fifteenth Kept N.Y. State Cab. Nat. Hist., p. 160, figs. 17-22, pi. iii, figs. 21,22. 
Meristella, Hall. Sixteenth Kept. N. Y. State Cab. Nat. Hist., p. 50, figs. 27-34. 
Meristella, Hall. American Journal of Science, vol. xxxv, p. 396; vol. xxxvi, p. 11. 
Mei'istella, Hall. Transactions of the Albany Institute, vol. iv, pp. 139, 140. 
Athyris, Billings. Proc. Portland Soc. Nat. Hist., vol. i, pp. 115, 116, pi. iii, figs. 13, 14. 
Charionella, Billings. Geology of Canada, p. 373, fig. 397; p. 374, figs. 400e, 401; p. 385, fig. 420. 
Merista, A. Winchell. Geol. Kept, of the Lower Peninsula of Michigan, p. 94. 
Meristella, Hall. Palaeontology of N. Y., vol. iv, pp. 295-299, 303-308, 420, plates xlviii, xlix, 1, 
figs. 1-17 ; Ixiii, figs. 15-22. 
Merista, Meek and Worthen. Geological Survey of Illinois, vol. iii, p. 376, pi. vii, fig. 8. 
Athyris, Nicholson. Palaeontology of the Province of Ontario, p. 86. 
Athyris, Billings. Canadian Naturalist and Geologist, vol. vii, new ser., p. 240. 
Meristella ( Whitjieldia), Walcott. Monogr. U. S. Geol. Survey, vol. viii, p. 148, pi. iii, fig. 8. 
Meristella, Nettelroth. Kentucky Fossil Shells, pp. 97, 98, pi. xv, figs. 2-8. 
Meristella, Simpson. Transactions of the American Philosophical Society, vol. xvi, p. 442, fig. 7. 
* Petrefactenkunde Deutschlands ; Brachiopoden, pi. li, figs. 69-75. 1871. 
t Dr. Davidson refers to preparations of Merista prunulum by Zugmaybr, and implies that there are 
some minor differences in the loop, etc., from these structures in M. hereulea. Dr. Zcgmayer’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 referred to Merista. 
