252 
Eelations and Differences. — Tins species differs from P. tenella, J, 
Dana, by its greater relative height, and its more elliptical aperture. 
Horizon and Localities. — According to Dana this species was found at 
Harper’s Hill. Mr. Clarke found it at Pallal on the Gwydir. 
Plaitceras tenella, J. D. Dana. 
PI. XXIII, Pig. 6. 
Dileopsis tenella, J. D. Dana, 1819, G-eol. Wilkes’ U. S. Explor. Exped., p. 786, pi. 9, fig. 13. 
This is a small, conical, recurved shell, with an oval aperture. It 
terminates at its posterior end in a sharp and prominent point. Its surface 
is smooth. 
Dimensions. — Its height is sis millimetres, and the antero-posterior 
diameter of its aperture eight millimetres. 
Eelations and Differences. — As I am not certain that this and the 
j)receding species are not young individuals of an unknown species with 
more decided characteristics, I have reserved for them, tentatively, the names 
under which Dana figured and described them. .P. tenella differs from P. 
altum by being less high, and by having a relatively broader and more 
oval aperture. 
Horizon and Localities. — According to Dana it is found in the lime- 
stone at Harper’s Hill. Mr. Clarke found it in a grey limestone at Colocolo. 
Genus — PODCELLIA, Lecielle} 
PoECELLiA WooDWARDii, JV. Martiur 
PI. XXIII, Pig. 8. 
C oncliyliolithus N. Ammonites JHoodioardii, W. Martin, 1809, Petrif. derbiensis, p. 
17, pi. 35, fig. 4, 5. 
Nautilus IVoodwardii, J. de Carle Sowerby, 1829, Min. Conch., VI, p. 138, pi. 571, 
fig- 3. 
1 {Liveillia, E. B. Newton, Gcol. Mag., 1891, VIII (.3), p. 203.— W.S.D.] 
^ [LeveilUa, WooduMrdi, R. B. Newton, Geol. Mag., 1891, VIII (3), p. 207. — W.S.D.] 
