NAPLES FAUNA IN WESTERN NEW YORK, PART 2 339 



protocalyptraea Clarke. 1894 

 This genus was introduced 1 for conical, crepiduliform shells in which the 

 apical spire is exposed, but beyond this no trace of the suture appears on 

 the exterior except on sculpture casts, the concealed part of the whorls 

 being represented in the interior by a spirally revolving and expanding 

 plate. The only representatives of this structure now known are the two 

 species here described, P. styliophila and P. marsh alii, and prob- 

 ably the Capulus galeroides Clarke from the corresponding horizon 

 (Ibergerkalk) at Riibeland in the Hartz. 2 



Protocalyptraea styliophila Clarke 



Plate 19, fig. 7-9 



Protocalyptraea styliophila Clarke, op. cit. p. 334 



Shell conic, erect, circular at base ; apical angle about 50 . Spire 

 exposed at the apex for one to two volutions, thenceforward on the shell 

 the only trace of volution is a low depression running along the suture. 

 Internal spiral plate (lower surface of whorls) flat, expanding, extending 

 one fourth the distance across the internal cavity. Surface marked by very 

 fine concentric lines. 



Dimensions. The original specimen has a hight of 12 mm, an aper- 

 tural diameter of 14 mm. 



Habitat. Genesee province ; Naples subprovince. Rare in the 

 Styliola limestone ; Genundewa, Canandaigua lake. 



Protocalyptraea marshalli Clarke 



Plate 19, fig. 1-6 



Protocalyptraea marshalli Clarke, op. cit. p. 334 



Shell conic, apical angle somewhat larger than in the preceding species. 

 Apical whorls exposed for one and one half volutions, and in compressed 



1 American species of Autodetus and some paramorphic shells from the Devonic 

 (Am. Geologist. 1894. 13:328). 



2 Fauna d. Ibergerkalkes. Neues Jahrb. fur Mineral. Beilbnd 3. 1884. p. 343, 

 pl- 5, % 12. 



