ORTHID Ai. 211 
ORTHIS ELEGANTULA, Dalman. Pl. XXVII, figs. l1—9; and Woodcuts, figs. 1 & 2, p. 205. 
ORTHIS ELEGANTULA, Dalman. Vet. Akad. Handl., p. 117, pl. ii, fig. 6, 1828. 
GONAMBONITES OBLONGUS, Pander, Beitr., pl. xxv, fig. 5, 1830. 
ORTHIS ELEGANTULA, Hisinger. Lethzea Suecica, p. 71, pl. xx, fig. 13, 1837. 
V. Buch. Ueber Delthyris und Orthis, Akad. Berlin, p. 36, pl. ii, 
figs. 3, 4,5, 1837; and Mém. Soc. Géol. France, vol. iv, p. 207, 
pl. xi, fig. 4, 1840. 
— caNaALis, J. de C. Sow. Silurian System, pl. xiii, fig. 12¢, 1839. 
Hail. Geol. Rep. 4th District N. York, p. 105, fig. 6; p. 107, 1843. 
—  ELEGANTULA, De Verneuil. Geol. of Russia, vol. ii, pl. xiii, fig. 5, 1845. 
M‘Coy. Synopsis Sil. Foss. of Ireland, p. 29, 1846. 
De Verneuil. Bull Soc. Géol. France, 2nd ser., vol. iv, 1847; 
and vol. v, p. 347, 1848. 
Dav. London Geol. Journal, pl. xiii, figs. 9—11, 1847; and 
Bull Soc. Géol. France, 2nd ser., vol. v, p. 321, pl. iii, 
fig. 23, 1848. 
Phillips and Salter. Mem. Geol. Survey, vol. ii, p. 287, 1848. 
Barrande. Sil. Brachiop. BGhmen; Naturw. Abhandl., vol. ii, 
p. 44, pl. xx, fig. 4, 1848. 
Bronn. Index Pal., vol. ii, p. 854, 1848. 
Salter. Quarterly Journal Geol. Soc., vol. vii, p. 170, 1851. 
J. Hall, Pal. New York, vol. ii, p. 252, pl. lii, fig. 3, 1852. 
M‘Coy. Brit. Pal. Foss., p. 216, 1852. 
F. Schmidt. Silurische Format. von Ehstlands, &c. ; Archiv Nat. 
Liv- Ehst- und Kurlands, p. 213, 1858. 
Salter. Siluria, 2nd ed., pl. ix, fig. 19, and pl. xx, fig. 12, 1859. 
Lindstrém. Gotlands Brachiopoder, p. 366, 1860. 
Salter. Mem. Geol. Survey Edinburgh (32), p. 134, 1861. 
et O. parva, M‘Coy. Brit. Pal. Foss., pp. 216 and 221, 1852. 
(including O. parva), Salter. Mem. Geol. Survey, vol. iii, pp. 
268, 276, 277, 279, 361, 1866. 
Haswell. Sil. Form. Pentland Hills, p. 34, pl. ii, fig. 19, 1865. 
Dav. Trans. Geol. Soc. of Glasgow, Pal. Series, vol. i, pl. ii, 
figs. 8, 9, 1868. 
Spec. Char. Longitudinally oval or ovate, broadest posteriorly or at a short distance from 
the hinge-line, sides rounded, converging anteriorly, rounded in front ; hinge-line shorter 
than the width of shell. Ventral valve uniformly convex and arched, without sinus ; beak 
moderately produced and incurved ; area triangular, about one fifth as high as long, fissure 
open. Dorsal valve nearly flat or gently convex laterally, with a slight, shallow, longitu- 
dinal depression or sinus commencing at the umbone, and gradually widening as it nears 
the front ; a small longitudinal fold sometimes occupies the centre of the depression ; hinge- 
area narrow. Surface marked by numerous thread-like radiating striz, not always very 
