222 
XATJTILOIDEA. 
Sp. Char. “ Shell compressed at the sides and somewhat flattened 
on the periphery, so that the whorls have a suhquadrate section. 
Umbilicus open, of moderate size, with rather steeply sloping sides, 
probably exposing the inner whorls, but the specimens are not com- 
plete enough to determine the amount of enrolment. Septa very 
numerous, thirteen in about half a volution ; sutures gently curved 
upon the sides of the shell and nearly straight upon the periphery. 
Internal (dorsal) lobe very conspicuous (see fig. 48, c). The cast is 
marked with a very distinct ‘ normal line ’ along the median line 
of the periphery (see fig. 48, a). Siphuncle below the centre. Some 
detached body-chambers, probably belonging to this species, have 
portions of the test preserved, and this is quite smooth, 
Remarlcs. “ This species appears to be nearly related to Nautihm 
ohesus (sec fig. 45), but it is distinguished by its closer septa, the 
position of its siphuncle, its more slender whorls, and narrower 
periphery. 
“ The specimens were all obtained in the Northamptonshire Iron- 
stone, and from most of them the shell has been dissolved away, 
leaving hollow spaces surrounding the casts.” (Foord and G. C. 
Crich.) 
Horizon. Inferior Oolite. 
Locality. Duston, Northamptonshire. 
Well represented in the Collection. 
Nautilus Baberi, Morris and Lycett. 
1850. Nautilus Baheri, Morris and Lycett, A Monogi-aph of the Mol- 
lusca from the Great Oolite, pt. i. p. 10, pi. i. ff. 1, 1 «. 
1854. Nautilus Baheri^ Morris, Catalogue of British Fossils, 2nd ed. 
p. 30G. 
1870. Nautilus Baheri, Sharp, Quart. Journ. Geol. Soc. vol. xxvi. 
p. 384. 
1871. Nautilus Baheri, Phillips, Geology of Oxford and the Valley of 
the Thames, pp. 177, 243. 
1873. Nautilus Baheri, Sharp, Quart. Journ. Geol. Soc. vol. xxix. 
p. 289. 
1875. Nautilus Baheri, Etheridge, in J. W. Judd’s Geology of Butlaud 
(Mem. Geol. Surv. GrCat Britain), p. 204, and Appendix, p. 288. 
8p. Char. “ A compressed, smooth shell, or only slightly marked 
by the lines of growth, with angular embracing volutions, leaving 
but a faint trace of an umbilical cavity ; aperture somewhat quadri- 
lateral, narrowed above, and wider than it is long ; the septa are 
slightly sinuous, curving towards the umbilicus and outer margin. 
“ This species is allied to N. truncatus, Sow., from the Lias, but ' 
