314 NEW YORK STATE MUSEUM 



convex, posterior sinus strongly developed toward the margin. Sculptured 

 by fine, sharp, elevated concentric and continuous concentric lines. 



Dimensions. Length and hight 4 mm. 



Observations. This little shell approaches in outline some of the forms 

 which Hall assigned to his species P. brevis from the Ithaca and 

 Chemung beds, but it attains an even more trigonal expression than any of 

 them and indeed in respect to form expresses the most extreme aberration 

 observed among species of the genus. 



Habitat. Genesee province ; Chautauqua subprovince. This rare 

 species has been seen only in the soft shales at forks of Cattaraugus creek, 

 Gowanda. 



Palaeoneilo linguata sp. nov. 



Plate 15, fig. 17-22 



To this genus are referred provisionally a series of subplane shells of 

 characteristic outline and contour, though little has been made of their 

 cardinal structure, all being rather indistinct sculpture casts. The shells 

 are transversely elongate with broadly rounded anterior and tapering 

 posterior moiety ; beak at about the anterior third, the margin in front 

 bending broadly outward in a semicircular curve, transverse on the basal 

 margin, passing to a sublinguate posterior extension and rounding thence 

 rather abruptly to a long, oblique and straight postcardinal slope. Contour 

 very depressed, almost flat over the entire surface, save along the hinge ; 

 beak obscure. Surface usually quite smooth or with obscure traces of fine 

 concentric lines. The casts show by compression a hinge area bearing the 

 characteristic denticulations of the genus Palaeoneilo. The species is 

 similar in its marginal outline to P. el on gat a of the Ithaca fauna. 



Dimensions. An average specimen has a length of 18 mm, a hight 

 of 10 mm. 



Habitat. Genesee province ; Chautauqua subprovince. These fossils, 

 obscure in all details of structure, are quite abundant in the soft sandy 

 shales at Forestville (Walnut creek and Terry's ravine), Chautauqua co. 



