IO8 NEW YORK STATE MUSEUM 



Grammysia modiomorphae Clarke 



Plate 27, figures 1-6, 8 



Grammysia modiomorphae Clarke. N. Y. State Mus. Bui 107. 1907. p. 221 



Shell large, elongate, generally with strong oblique medial depression 

 dividing the valves into two lobes, sometimes a low ridge lying in the bot- 

 tom of this depression ; beaks at the anterior one third of the hinge, slightly 

 elevated, appressed and incurved ; hinge line direct, not elevated ; marginal 

 outline incurved in front of the beaks, rather narrow at the anterior extrem- 

 ity, broadly incurving on the basal margin at the median sulcus, recurving 

 in a broad angle at the postlateral extremity. The median sulcus varies in 

 width and strength in different examples, at times being highly and some- 

 what unequally developed on both valves, rather more on the right and 

 again being only a low, broad depression. 



Muscle scars obscure, only the anterior abductor being occasionally 

 shown on our specimens. Surface markings concentric striae strongly 

 marked at the anterior margin. 



The elongate form of this shell and its subsequent extremities give it 

 the appearance of a Modiomorpha. The evidence seems to indicate how- 

 ever that it is a Grammysia of unusual expression, with which it is not 

 easy to find comparison among other shells. Drs Kayser and Drevermann 

 who have kindly examined specimens of the shell agree that it is very similar 

 to Beushausen's G. prumiensis 1 from the upper Coblentzian of the Eifel. 



Locality. This species is the most abundant of the lamellibranchs at 

 Edmunds Hill. 



Grammysia sp. 



With G. modiomorphae occurs a somewhat allied shell with 

 umbonal ridge high, convex and close upon the hinge, a low submedian 

 depression and very narrow anterior extremity. It appears to be an unde- 

 scribed species and I should regard its generic position as undetermined. 



Locality. Edmunds Hill. 



Leptodomus communis Clarke 



Plate 28, figures 8-10 



Leptodomus communis Clarke. N. Y. State Mus. Bui. 107. 1907. p. 224 



Shell elongate with a Cimitarialike curve to the hinge, beak anterior, 

 hinge not equaling the length of the shell ; lower margin sinuate, curving 

 upward posteriorly to a narrowed, subacute extremity whence the posterior 

 edge retreats to the hinge. Surface deeply silicate from umbo to basal 



'<?/. cit. p. 243, pi. 24, fig. 2-4. 



