NAPLES FAUNA IN WESTERN NEW YORK, PART 2 23 1 



flat, slightly elevated at their edges, and are crossed by subequidistant, fine, 

 elevated concentric striae which curve upward on the ribs and downward in 

 the furrows. 1 The surface is also crossed at irregular distances by coarser 

 concentric lines of growth. The number of radial ribs varies from 28 to 

 45, rarely exceeding 30. 



Dimensions. A full grown and normally rotund individual measures 

 as follows : length 43 mm, hight 50 mm ; length of sical margin 30 mm. 



Habitat. Genesee province ; Naples subprovince. This species is 

 generally disseminated throughout the Naples shales in Yates, Ontario, 

 Livingston and Genesee counties. It has been found at various outcrops 

 in Naples, on Honeoye and Conesus lakes, at Belknap's gully near Branch- 

 port, -along the Cashaqua creek, and rarely on the Genesee river. It is 

 quite rare in the sandy layers of the upper beds and is not known as. yet 

 even in the lower layers of Erie county. 



Lunulicardium (Pinnopsis) ornatum Hall. 1843 



Plate 1, fig. 8-14 



Pinnopsis ornata Hall, Geology of New York; report on the fourth district. 



1843. P- 2 44, fig- 106, 108 

 Lunulicardium ornatum Hall, Preliminary Notice Lamellibranchiata. pt 2 



1870. p. 91 

 Lunulicardium ornatum Hall, Paleontology of New York. 1885. v. 5, pt 1. 



P- 437, pl- 71, fig- 2 5. 2 9 

 Lunulicardium 'ornatum Clarke, U. S. Geol. Sur. Bui. 16. 1885. p. 61 



Diagnosis. Shell often of large size, outline suborbicular or obliquely 

 subelliptic ; beak projecting; apical angle iio°— 115 . Posterior or sical 

 margin straight or slightly incurved, extending to about the middle of the 

 shell, its actual length being approximately three fifths the length of the 

 valve. 



Surface regularly convex, the line of greatest convexity being toward 

 the anterior margin ; the slope thence posteriorly is gradual, and sometimes 



x Just the reverse of their direction as represented in Paleontology of New York. 

 v. 5, pt 1, pl. 71, fig. 32. 



