i iZ PALZONTOLOGY OF NEW-YORK. 
222. 10. PLEUROTOMARIA SUBTILISTRIATA (n. sp.). 
Pu. XXXVI. Figs. 5 a, b, ¢, d. 
Lenticular ; spire much depressed ; volutions four or five, even, smooth, forming a very 
depressed cone, with an elevation little more than one third the width of the shell ; aperture 
transversely extended into a somewhat triangular form; umbilicus very small ; surface 
marked by fine close striz, which bend gently backwards on the upper half of the volution, 
and more abruptly on the lower half, finally running almost parallel to the outer margin ; 
outer margin of last volution sharply angular, with a mesial band parallel to the edge, 
indicating the generic character of the shell. 
This species is much smaller and more depressed than either of the others, most of the 
specimens being scarcely visible to the naked eye. The surface is apparently smooth, but 
under a magnifier, is clearly marked by fine striz as described. The outer volution is 
slightly concave near the margin, the others being plane. 
Fig. 5 a. View of the spire of a large specimen. 
Fig. 5 b. Profile of the same. 
Fig. 5 c, d. View of the spire and profile of the largest specimen seen. 
Position and locality. This species is known to me only as occurring in the concretionary 
and irregularly bedded limestone, near the base of the Trenton limestone, at. Watertown, 
Jefferson county. 
923. 11. PLEUROTOMARIA LENTICULARIS. 
Pu. XXXVII. Figs. 6 a, b, c, d. 
Trochus lenticularis (?}) Sowrrsy in Sil. Researches, 1839, pag. 642, pl. 19, fig. 11. 
Pleurotomaria lenticularis, Conrap in MS. Emmons, Geol. Report, 1842, p. 392, f. 2; p. 393, f. 2 & 3. 
Compare Helicites qualteriatus, ScHLOTHEIM, 1820, Petrefacta, p. 103; Iv. Nachtrage, pl. 11, fig. 3. 
— obvallatus, WAHLENBERG, 1821, Act. Soc. Sci. Upsal, Vol. viii. pag. 73, pl. 4, f. 1 & 2. 
Solarium petropolitanum, PANDER, 1830, Beitrage zur Geogn. Russland, pag. 150, pl. 1, fig. 3. 
Euomphalus pseudoqualteriatus, Von Bucn, 1830, Karst. Archiv, p. 156 - 158. 
Delphinula obvallata, HistncEr, 1831, Petrif. de la Suede, p. 8. 
Euomphalus qualteriatus, Goupruss, 1834, in Kloden Verst. Brandenburg, p. 155. 
— _— Bronn, 1835, Leth. Geognostica, pag. 94, pl. 2, fig. 1. 
_ pseudoqualteriatus, HistvcrR, 1837, Leth. Suecica, pag. 36, pl. 11, fig. 5. 
— qualteriatus, Escuwap, 1840, Sil. Syst. in Esthland, p. 115. 
— — GoupFuss, 1844, Petref. Germanice, Vol. iii. pag. 81, pl. 189, fig. 3 a, bd. 
— — VERNEUIL, 1845, Pal. Russia and the Ural Mountains, pag. 333, pl. 23, 
fig. 1 a,b; and var. A. fig. 2 a, d. 
Not Pleurotomaria lenticularis, Goupruss, Petrefacta, Vol. il. pag. 65, pl. 183, fig. 2. 
Lenticular ; spire depressed, subdiscoidal ; volutions scarcely four, flattened above, last 
one obtusely angular at the margin and somewhat ventricose below ; aperture transversely 
extended, subtrigonal ; umbilicus large, extending to the apex ; surface marked by fine 
stria, which curve gently backwards from the suture, making an abrupt retral bend in 
passing over the angles of the last volution. 
