266 LrHE DEVONIAN FOSSILS OF CANADA WEST. 
BRACHIOPODA. 
Genus Lancuta.—(Bruguiére.) 
Of this genus, only one species has been found in the Devonian 
rocks of Canada West. The specimens are too imperfect for de- 
scription. 
STREPTORuUYNCUS PanpoRaA.—WN. Sp. 
Fig. 13. 
Fig.12. Streptorhyncus Pandora.—View of the dorsal valve. 
Fig. 13.—Longitudinal section. 
Description.—Shell semioval, or sub-quadrate ; length about three- 
fourths the width, hinge line equal to the greatest width of the shell, 
sometimes a little less, usually forming a right angle with the sides of 
the cardinal extremities; front margin broadly rounded. Ventral 
valve depressed semiconical, most elevated at the beak, thence de- 
scending with a slightly concave or nearly flat slope in all directions, 
to the margin. Area of ventral valve, large triangular, extending the 
whole length of the hinge line, sloping outwards at an angle of about 
100°, with the plane of the lateral margin ; foramen triangular, very 
conspicuous, its width at base nearly twice the height, nearly or 
altogether closed by a convex deltidium. Dorsal valve moderately 
convex, gently compressed towards the cardinal angles. Surface 
with very narrow, strongly elevated, radiating ridges, of which there 
are from four to six in the width of one line; the increase appears 
to be both by bifurcation and interstitial addition, the latter mode 
being the most common. 
Width of a specimen of medium size, sixteen lines ; length of same, 
from the beak of the ventral valve to the front margin, twelve lines ; 
height of area of ventral valve at the beak, two lines and three- 
fourths ; width of foramen at base, four lines anda half. Another 
specimen is twenty lines wide and sixteen in length. Besides these, 
