298 NEW YORK STATE MUSEUM 



The grooves are regularly concave, and are smooth ; faint traces of con- 

 centric lines on them are sometimes seen on the anterior slope. These 

 grooves are always narrower than the ribs, and on the ventral margin have 

 about two thirds of their width. 



Dimensions. The length of this shell rarely exceeds 8 mm, the average 

 of size being considerably less than this. An uncompressed valve of this 

 length from the Styliola limestone has a convexity of 3.5 mm. 



Habitat. Genesee province ; Naples subprovince. Not infrequent in 

 the Styliola limestone on Canandaigua lake. Also in a higher limestone, 

 just beneath the sandstones, at Lodi, Seneca co. Everywhere in the argil- 

 laceous and sandy shales of the Naples beds in Seneca, Ontario, Living- 

 ston, Genesee and Wyoming counties, rarer in the lower beds of Erie 

 county, and occasionally in the eastern extension of this fauna through 

 Schuyler, Tompkins, and into Cortland counties. Also in the Wiscoy 

 shales above the Portage sandstones. 



Buchiola stuprosa sp. nov. 



Plate 10, fig. 23, 24 



Glyptocardia speciosa Hall, Paleontology of New York. 1885. v 5, pt 1, 

 pi. 70, fig. 2-4 , 



In the work cited Professor Hall included with typical Glypt. spe- 

 ciosa from the Portage shales, specimens from the black Genesee shales, 

 figured as above. These, which we have had redrawn in part because their 

 characters were not accurately given, are of rather inferior preservation, but 

 they are clearly distinct from the other species here described, in the fol- 

 lowing respects. They are quite elongate transversely, narrower in front 

 than behind, the ribs are few, nine to 11, quite broad and flat with narrower 

 interspaces, margins elevated on those in front of the umbo but otherwise 

 with rounded edges, all ribs becoming more obscure and even obsolescent 

 toward the margins. The concentric lines are faint, but fine, elevated, 

 turned backward in a broad curve on the ribs and visible also in the sulci. 



In size the shells measure 6-8 mm in length by 5-6 mm in hight. 



Habitat. In the black Genesee shales of Bristol, Ontario co. 



