100 DEVONIAN FAUNA. 
connecting it with the typical shape of M. plebeia there may be reason to think 
that Davidson is right in uniting it with this species, but its spheroidal shape is 
certainly remarkable. Mons. Cihlert is inclined to regard it as distinct. 
M. plebeia is frequently marked with coarse growth-ridges. 
It appears to me that Kayser has reason for uniting M. prunulwm, Schuur, 
with Sowerby’s species; and that Maurer’s version of that shell is only a some- 
what elongated variety, which is very similar to some English specimens of it. 
Meristella Circe, Barrande,' as given by Barrois,” looks exactly like our shell, 
but he intimates that it differs generically, being without the shoe-lifter process. 
Merista passer, vultur, and Calypso, Barrande,’ all closely resemble different 
specimens of the English shell, and I think they are only larger varieties of it. 
2. Genus.—Atuyris, McCoy, 1841. 
1. Atuyris Guassu, Davidson. 
1882. ArvHyRis Guassi1, Davidson. Brit. Foss. Brach., vol. v, pt. 1, p. 24, pl. i, 
figs. 21, 22. 
1885. — — Maurer. Abhbandl. Grossh. Hessisch. Geol. Landes. 
vol. i, pt. 2, p. 164, pl. vii, figs. 7—7 e. 
Size.—Length, 14 mm.; breadth, 13 mm.; depth, 7 mm. 
Localities —From Lummaton are seven specimens in my Collection, and from 
Wolborough three in Mr. Vicary’s Collection. 
Remarks.—This species seems recognised by its flattish transverse shape, 
sharp uncurved beak, and smooth surface. 
2. AtHyRIS conceNTRICA, Von Buch. 
1831. TrREBRATULA CONCENTRICA, von Buch. Abhandl. Konig]. Acad. Wissen. 
Berlin, p. 103. 
1864. ATHYRIS CONCENTRICA, Davidson. Brit. Foss. Brach., vol. iii, pt. 6, p. 14, 
pl. iii, figs. 11—15, 24. 
1868. SprriezRA concenTRICA, Dames. Zeitsch. Deutsch. Geol. Gesell., p. 496, 
pl. x, figs. 6, 7. 
1882. AtTHyYRIs concENTRICA, Davidson. Brit. Foss. Brach., vol. v, pt. 1, p. 25, 
pl. i, figs. 23, 24; and pl. ii, figs. 10, 
10 a. 
1 1879, Barrande, ‘Syst. Sil. Bohém.,’ vol. v, pl. xv, fig. 4, 1-10, and pl. exlii, fig. 8, 1-3, Et. F. 
2 1889, Barrois, ‘Mém. Soc. Géol. Nord,’ vol. iii, p. 105, pl. vi, figs. 5—5 e. 
3 1879, Barrande, ‘Syst. Sil. Bohém.,’ vol. v, pls. xii, xiv, xciv, exxxiv, exxxv, exxxvi, and exlii, 
Et. F. and G. 
