174 PALEONTOLOGY OF NEW YORK. 



Tliis species differs from L. Chemungensis in its more erect form, and tlic car 

 is without the strong fold and marked sulcus of tli.it species: tin- wiuLr is alsn 

 less extended and the margin less concave. 



Formation and locality. In the (Jhemung group in the valley ol' Cayutu creek, 

 Broome county. N. Y. 



LeIOI'TEEIA TullKEVI, n. sp. 

 n.ATK XXII. riGS. G, 7; and pl.vte lxxxvui, fk;. n 



SiiKi.L ol' nu'diuni size, rhomboidal, sub-falcate; body narrow-ovate, arcuate, 

 ol)lique at an angle of less than 45° wdth the iiinge ; height equal to al>out 

 two-thirds of the length ; anterior and basal margins broadly curving liom 

 the byssal sinus; post-basal margin ])roduced and abruptlv recurved. 



Left valve very convex, gibbous in the middle and above. Right valve 

 unknown. 



Hinge-line straight, al)Out equal to the height of tin- valve. 



Beak sul)-anterioi", directed forward, acute, prominent and aicliing over 

 the hinge. Umbonal region narrow, vcntricose, well-defineil, subtending an 

 acute angle. 



Ear large, bending downward, marked by a strong oblique fold, limited ly 

 a broad, vertical byssal depression and shallow sinus; niai-gin convex; 

 extremity ap})arently obtuse. Wing joining the body above the posterior 

 extremity, limited liv the nearly vertical post-nnd)onal slope, which makes a 

 more or less nuirked sulcus; margin concavi' : extremity proiluccd. acute. 



Surface marked by fine striae of growth which are somewhat reguiarh' 

 lamellose on the body of the valve. 



A left valve has a lc)i;:tli of "J'.l inni., lieiglit 'I'l nini., bingc-liiu> ill mm. 



This species dilfers from L. Chemungensis in its proportionally greater lengtii. 

 narrower umbo, more convex and oblique left val\ e, and shorter wing. 



Formation and locality. In a sandstone and conglomerate of the ("biiiiuug 

 group near Panama, N. Y. 



