' >'VA, 



246 PALAEONTOLOGY. 



half as wide as the cylindrical portion below, which appears to be smooth 

 and destitute of rings. Lateral lobes also marked by a single, wide, flat- 

 tened rib, corresponding to the annulation of the axis, and a narrow, 

 sharply-elevated,, anterior ridge, corresponding to the articulating projection 

 of the axis. 



The p3^gidium is all that has yet been recognized of this peculiar spe- 

 cies, but it is so marked in its characters that we have no hesitation in pro- 

 nouncing it distinct from any hitherto described. The absence of rings 

 on so great a length of the axial lobe is a marked and distinguishing feature. 



Formation and locality/. — In greenish shales of the age of the Quebec 

 group, at East Canon, Oquirrh Mountain's, Utah. Collected by S. F. Emmons 

 and J. E. Clayton. 



FOSSILS OF THE DEVONIAN. 



BRACHIOPODA. 



Genus STROPHODONTA Hall. 

 Strophodonta Canace. 



Plate III, figs. 1-3. 



Strophodonta Canace H. & W., 23d Eept. St. Cab., p. 230, pi. II, figs. 8-11. 



Shell of medium size, subquadrangular in outline, wider than long; 

 hinge-line a little shorter than the greatest width of the shell, the external 

 border very gently sloping from the middle to the extremities; lateral mar- 

 gins and basal border of the shell somewhat straightened, and the angles 

 rounded. Ventral valve convex, slightly geniculated near the middle of its 

 length, and flattened on the umbonal disk ; cardinal area narrow, sublinear 

 or moderately decreasing in width from the middle outward, vertically 

 striated or crenulate and divided in the center by a narrowly triangular 

 fissure. Dorsal valve concave, a little more than half as deep as the con- 

 vexity of the ventral; area very narrow. Surface of the ventral valve 

 marked by strong, sharp, distant, radiating striae, with concave interspaces, 

 which are occupied by three or more finer, even striae. Surface of the 



