56 
PALAEONTOLOGY OF NEW YORK. 
Internal characters not known. 
The specimen described, is a right valve, having a length of 34 mm., 
height 36 mm., and hinge-line about 10 mm. 
In outline and surface characters this species resembles L. Priamus, but the 
valve is more convex than the specimen referred to the right valve of that 
species; it is also less oblique, and the beak more elevated and erect. The 
rays of L. Priamus are distinctly and frequently bifurcating, while in this 
species the fasciculate appearance is due to the sharp, elevated striae upon the 
stronger rays. 
Formation and locality. Chemung group, Leon, Cattaraugus county, N. Y. 
Lyriopecten solox. 
PLATE XXIV, FIG. 5. 
I/yriopceten solox, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 24, fig. 5. Jan., 1883. 
Shell of medium size, nearly circular; transverse axis not inclined to the hinge¬ 
line ; margin regularly rounded, and sloping somewhat abruptly into the 
byssal sinus. 
Right valve moderately convex. Left valve unknown. 
Hinge-line straight, length about one-half the diameter of the shell, 
extending farther on the anterior side. 
Beak obtuse, rounded, central, not rising above the hinge-line, directed 
slightly forward ; umbo ample. 
Posterior ear triangular, defined by its flattened surface, and the rapid 
umbonal slope; margin concave; extremity rectangular. Anterior ear 
imperfect, but showing a very deep and narrow byssal sinus. 
Test marked by numerous fine, angular rays, which are arranged in about 
40 regular, rounded plications, composed of fascicles of finer rays, with 
defined interspaces. Finer obscure rays mark the umbo, and the posterior 
ear shows three or four rounded undulations with lines of growth. 
Interior not known, except the ligamental area, which is narrow, and 
makes an inflection of the hinge-margin of the ears. 
