NAPLES FAUNA IN WESTERN NEW YORK, PART 2 325 



is in error in stating that Hall ever applied the name Phragmostoma to 

 such shells. In the characters indicated above as peculiar to the Genus 

 Ptomatis, Bell, rhenanus is apparently in accord, except for the 

 presence of revolving surface lines, and it may be quite properly 

 associated with Ptomatis patula and Pt. forbesi. 



Returning then to the standing of the term Phragmostoma, we may 

 observe that, as in its original use it has proved a synonym of Carinaropsis, 

 it is quite legitimate to employ it for the species B. n a t a t o r, the only form 

 except those of Carinaropsis to which its author applied the term. As the 

 first and second species ascribed to Phragmostoma belong to another genus, 

 the third (P. n at at or) will serve as the type species. In this sense we 

 revive and delimit the term. 



Diagnosis. Shells with short spiral, very broadly expanded peristome, 

 transected on the inner margin by the penultimate whorl, narrow and 

 sharply defined slit band. Surface with revolving lines, sometimes with 

 low lateral carinae. The callus on the inner lip is thick, flattened and 

 angular on its inner edge, and thus has a wedge-shaped appearance, which 

 when under compression appears septiform, but does not make a true 

 septum or transverse plate. 



Phragmostoma natator Hall 



Plate 16, fig. — 



Bellerophon expansus (Sow.?) Hall, Geology of New York ; rep't on fourth 



dist. 1843. p. 244, fig. 3 

 Phragmostoma natator Hall, N. Y. State Cab. Nat. Hist. 15th An. Rep't 



1862. p. 60 (not pi. 6, fig. 12-14) 

 Phragmostoma natator Hall, Illustrations of Devonian Fossils. 1876. pi. 23, 



fig. 12 

 Bellerophon natator Hall, Paleontology of New York. 1885. v. 5, pt 2, 



p. 108, pi. 24, fig. 1 



Bellerophon n a t a t o r Clarke, U. S. Geol. Sur. Bui. 16. 1885. p. 52 



The original specimen of Bell, expansus Hall was a portion of the 



aperture and final whorl, the spiral being destroyed, in a quite characteristic 



style of preservation in the soft Portage shales. That subsequently figured 



in the Paleontology of New York was a similar fragment stated to be from 



