MARCELLUS LIMESTONES OF LANCASTER 167 



Meristella meta Hall 



Pal. X. Y. 4:308, pi. 49 



A well preserved specimen in bed I is referred to this species. 

 It differs from Meristella barrisi in the smaller size 

 and in the presence of a distinct angular sinus beginning about 

 one third of the distance from posterior to anterior margin. The 

 cardinal slopes are somewhat flattened. 



PELECYPODA 



PANENKA Barrande 

 Panenka mollis Hall 



Pal. N. Y. Tol. o, pt 1,, p. 420, pi. 80 



One specimen apparently of this species was found in bed VIII. 

 It is smaller than the type, being only 8.6 mm high, by 9.2 mm 

 long, but it agrees with the latter in other respects. 



Panenka lincklaeni Hall 



Pal. X. Y. vol. 0, pt 1, p. 420, pi. 69 



This species has not been observed at the Plumbottom creek 

 locality, but appears to be fairly common in bed I at the corner 

 of Buffum and Seneca streets, Buffalo. The specimens are nearly 

 perfect casts showing the flattened distant plications and rounded 

 form characteristic of the species. A shell of average size is 59 

 mm long, and 50 mm high. 



LEPTODESMA Hall 



Leptodesma marcellense Hall 

 PI. 9, fig. 16, 17 



Pal. y. Y. vol. 5, pt 1, p. 175, pl. 17 



Associated with specimens which show the normal character- 

 istics of the species are others somewhat less oblique. The char- 

 acter and amount of variation may be seen by a comparison of 

 the drawings here given, from specimens from beds II and 

 V. A single nearly perfect specimen was found in bed C of the 

 lower shales. 



