TRIBE BRACHIOPODA. 333 



Minute, more or less orbicular or semicircular, retuse ventrally, 

 depressed, subequivalve, horn-coloured, shagreened, but otherwise 

 smooth ; mesial groove distinct ; hinge-line straight, much produced ; 

 hinge-area depressed, triangular ; perforation very large, intruding 

 upon the lower valve : inner edges radiatingly scabrous : a single 

 median septum, and a two-lobed loop. i. Zetland. 



LINGULA. 



Thin, subequivalve, equilateral, ovate-elongated, depressed, subtrun- 

 cated at one end, subacute at the other, fixed to a peduncle ; devoid of 

 hinge or ligament ; muscular impressions several in each valve, arranged 

 in pairs. 



L. Anatina. Lam. Syst. Anim. — Lam. 1. — Bl. £.51,/. 3. — Sow. G. 

 Ling. f. 4, 5.— Reeve, C. S. t. 125, /. 3. — Kust. vii. 1, 1. 1,/. 1, 2, 3. — 

 Sow. Th. 1, p. 337, t. 77, /. 1, 2, 3, 9, 10.— Mytilus Lingua, D.p. 322. 

 — W. 1. 12,/. 45. Oblong, compressed, slightly striated longitudinally, 

 equal in width at both ends, green or brown ; broad end somewhat 

 trilobate : one of the valves longitudinally thickened near the centre 

 within. 1£. Philippines and Moluccas. 1 



L. Hians. Swains. Phil. Mag. 62.— Sow. Th. 1, p. 388, t. 77, /. 4.— 

 ? L. Antonii, Kust. vii. 1, t. 1, /. 7, 8, 9. Elongated-oblong, very 

 thin, rather narrow, greenish ; gradually attenuated and rather convex 

 towards the tapering extremity. \...lf. China. 



L. Audebardi. Brod. Z. P. 1833, p. 100 ; Z. T. 1, p. 2, t. 3,/. 14. 

 — Desk. Lam. 7, p. 390.— Reeve, C. S. t. 125, /. 1.— Sow. Th. 1, 

 p. 392, t. 67, /. 5. Elongated-oblong, glabrous, pale yellow, con- 

 centrically painted with green ; broader extremity somewhat square- 

 shaped (in the dried individual), adjacent to it the valves are a little 

 contracted, but again swell out before the final attenuation. 1. Bay 

 of Guayaquil. 



L. Semen. Brod. Z. P. 1833, p. 100 ; Z. T. 1, p. 2.— Sow. Thes. 

 Conch. 1, p. 392, t. 67, /. 11. Ovate-oblong, thickish, flattened, 

 whitish, very smooth and polished; broader end rounded. £...y. 

 W. Columbia. Resembling a melon-seed in size and appearance. 



L. Tumidula. Reeve, Z. P. 1841, p. 100 ; C. S. i. t. 125,/. 4.— 

 Sow. Thes. Conch. 1, p. 393, t. 67,/ 7. Broader in proportion than 

 any known species, thin, horny, subquadrate, of a rufous colour, 



1 Compare with this the Pinna Unguis seu Lingua of Ch. f. 1675, 

 6, 7, termed L. Chemnitzii by Kuster (vii. 1, t. 1, f. 7, 8, 9). 



