NAVTIL1D.E. 
Go 
appearance to the suituce of the test. The septa and sipliuiiele are 
not seen. 
Fig. o. 
Gyroceras Hibiruicum. — a, lateral view, sliowing tlie ornaments ami the 
initial point of the shell ; b, front view, showing the tine longitudinal 
ridges. Drawn from a Sjieeiinen in the Collection. Natural size. 
lieimnks. This species is very closely allied to dyroceras onm- 
tisnlmiim, de Koninck, sp., but the sculpture, though of similar 
character, is much coarser. 
Horizon. Carboniferous Limestone. 
Locality. Near Dublin. 
Kepresented in the Collection by two examples. 
Gyroceras ornatissimum, de Koninck, S]>. 
1;^47. XuutUus Leveiileanus, d'Oibigny, Faleontologie Univer.selle, \ ol. i. 
pi. Ixxxix. ff. 1-4. (Aot of de Koninck.) 
1840. Nautilus Leveiileanus, d’Orbigny, Prodr. de l^ileont. Slratigr. 
vol. i. p. 110. {Not ofde Koninck.) 
1878. Nautilus ornatissimus, de Koninck, Faiine da Calc. Carb, de la 
Delgiqiie, pt. i. (Annales dii Mus. Uoy. d’llist. Nat. de Delgiipie, 
tom. ii.) p. 14o, pi. xxix. f. G. 
aS^>. Char. {Shell of medium size, discoid, composed of two and a 
half to three whorls, the last of which projects beyond the rest for 
an unknown distance. The whorks increase slowly in diameter, 
they are all exposed, and there is a large central vacuit 3 ^ The 
PAKT II. p 
