LAMELLIBRANCHIATA. 497 



Glossites lingualis, n. sp. 



PLATE XL, FIGS. 16, 19 ; and PLATE XCVI, FIGS. 9 11. 



In part Modiomorphaf amygdalina (Wiitcubll), Hall. Prelim. Notice Lamellibranchiata, 2, p. 78. 1870. 

 " " " " " Pal. N. Y., vol. V, pt. 1. Plates and Explana- 



tions : PI. 40, figs. 12-20. 1883. 

 Not Sanguinolites amygdalimis, Winchbll. Proc. Acad. Nat. Sci., Phila., p. 13. 1863. 



Shell of medium size or larger, elongate-sub-elliptical ; length usually a little 

 more than twice the height ; basal margin gently curved. Posterior extrem- 

 ity narrowly rounded. Cardinal margin slightly arcuate. Anterior end 

 somewhat produced, declining from the beaks to about the middle of the 

 height and abruptly rounded below. 



Valves depressed-convex below the middle and on the posterior portion, 

 becoming moderately convex in the umbonal region. 



Beaks at about the anterior fourth or fifth, small and closely appressed, 

 not rising above the hinge-line. Umbonal slope not defined. Some speci- 

 mens show a slight flattening or constriction of the valves extending from 

 the beaks to the base. 



Test marked by fine striae of growth, which are often fasciculate on the 

 body of the shell producing undulations of the surface. 



The cardinal border is distinctly flattened and there are indications of an 

 elongate tooth posterior to the beaks. The upper anterior margin is also flat- 

 tened in the cast, and this feature probably indicates the limits of the lunule. 



Four specimens measure respectively 30, 32, 39 and 56 mm. in length, and 

 14, 14, 18 and 25 mm. in height. 



This species is distinguished from G. depressus by its longer anterior end, 

 more elongate elliptical form ; and the cardinal line is not oblique, as in that 

 species. 



Specimens are abundant in some parts of the Chemung group, and are sub- 

 ject to considerable variation, due to the nature of the matrix and the condi- 

 tion of preservation. 



Formation and localities. In the Chemung group at Phillipsburgh, N. Y., and 

 at Mansfield, Pa. 



