56 PALAEONTOLOGY OF NEW YORK. 



Internal characters not known. 



The specimen described, is a right valve, having a length of o4 mm., 

 heighl 36 mm., and hinge-line about 1<> nun. 



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 

 Bpecies; it is also less oblique, and the beak more elevated and erect. The 

 rays of />. Priamus are distinctly and frequently bifurcating, while in this 

 species the fasciculate appearance is due to the sharp, elevated stria 1 upon the 

 stronger ra\ s. 



Formation and locality. Chemung group, Leon, Cattaraugus county, N. Y. 



Lyriopecten solox. 



I'l \TK XXIV, FK. 5. 

 Lyriopecten solar, Hall. Pal. N. Y., vol. v. pt 1. Platos and Explanations: PI. 24. fig-. 5. Jan., 1SS3. 



Shell ut' medium size, nearly circular; transverse axis not inclined to the hinge- 

 line ; margin regularly rounded, and sloping somewhat abruptly into the 

 byssaJ 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 

 Blightly forward; umbo ample. 



Posterior car triangular, defined by its flattened surface, and the rapid 

 umbonal slope; margin concave; extremity rectangular. Anterior ear 

 imperfect, bul showing a very deep and narrow hyssal sinus. 



Test marked by numerous line, angular rays, which are arranged in about 

 Hi 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. 



