238 
DESCRIPTION OF THE FOSSILS. 
concave. In a magnificent specimen belonging to Mr. Gilbertson, and in another in the 
Museum of the Yorkshire Philosophical Society, the siphuncle is expanded between the 
septa and its external surface there reticulated. 
O. filiferum-. Ph. Kulkeagh. 
Elongate, septa rather distant, siphuncle nearly central ; shell girt with fine regu- 
lar thread-like striae. 
O. ovale. Ph. Castleton ; Queen’s County. 
Elongate, section broad-oval, siphuncle a little excentric, septa without wave. 
O. unguis, Ph. PI. XXL fig. 2. Bolland. 
Suddenly arched toward the blunt end ; section circular. '< 
O. fusiforme. Sow. PI. XXI. fig. 14, 15. Bolland ; Kildare. 
Pyriform, arched in the smaller part, tumid near the aperture ; section oval, si- 
phuncle one-third of the diameter from the edge, shell smooth. In the specimen figured, 
the large projecting plate with its plane parallel to the axis, and to the longer diameter 
of the shell, is covered on the convex side by a white laminated friable inner shell, (a) 
very analogous to the ‘ bone’ of Sepia officinalis and to the lower lamina? of Belem, qua- 
dratus. My Kildare specimen does not shew it. 
O. undulatum. Sow. PI. XXI. fig. 8. Bolland; Castleton; Cumber- 
land. 
Section broad-oval; septa numerous, oblique, fiattish, their edges rising with a 
wave on each side ; siphuncle near the upper broad edge. 
O. Breynii. Mart. t. 39, Sow. t. 60. Kulkeagh ; Bowes. 
Section long-oval, the siphuncle in one focus, near the higher edge ; septa very 
oblique, approximate, shallow. 
O. inequiseptum. Ph. PI. XXI. fig. 7 - Bolland. 
Section round, septa very distant in the young shell. 
O. arcuatum. Ph. Clane, Kildare. 
A short conical shell, arched to the small end, with frequent septa, the siphuncle 
marginal on the convex side of the curve. 
O. Steinhaueri. Sow. PI. XXI. fig. 5. Bolland ; Halifax, in coal 
shale. 
Elongate, section circular, septa distant, very concave ; siphuncle marginal, shell 
annuloso- striate. 
O. angulare. 1 h. PI. XXI. fig. 4. Bolland ; High-Green- wood. 
Subcylindrical with a few longitudinal furrows ; septa very distant. 
O. reticulatum. Ph. PI. XXI. fig. n (cast). Bolland. 
Elongate, section circular, septa distant ; surface annulated, and reticulated with 
moniliform lines. 
