NAIJTILID^. 
297 
bigny, in its general form, but it has a much wider shell, and the 
siphuncle is nearer the outer margin of the septa. 
Horizon. Upper Chalk. 
Locality. Maestri cht (Limburg), Belgium. 
Bepresented in the Collection by an imperfect specimen. 
Nautilus Heberti, Binkhorst. 
1793. Hantilite Silicieu.v, Faiijas de Saint-Fond, Histoire Naturelle de 
la Montagne de Saint-Pierre de Maestricht, p. 139, Atlas, pi. xxi. 
f. 1. 
18')9. Nautilus Dekayi, Binkhorst, Esqnisse Geologique et Paleontolo- 
gique des Couches Cretaces du Limbourg, pp. 8, 38, &c. {Not of 
Morton.) 
18(31. Nautilus Heberti, Binkhorst, Mon. des Gasteropodes et des 
Cephalopodes de la Craie Superieur du Limbourg, p. 13, pi. v. h. 
ff. 1 a, 1 b. 
187(3. Nautilus cf. Heberti, Schliiter, Cephalopoden der oheren Deut- 
schen Kreide, Ahth. ii. (Palaeoutographica, Band xxiv.), p. 181 
((31). 
1879. Nautilus Heberti, Ubaglis, Bescr. Geologique et Paleontologique 
du Limbourg, p. 201. 
1881. Nautilus Heberti, iMourlon, Geologie de la Belgique (Listes des 
Fossiles), vol. ii. p. 101. 
^p. Char. Shell inflated, periphery rather narrowly rounded, 
flowing uninterruptedly into the sides of the shell ; greatest breadth 
in the umbilical region. Umbilicus exceedingly small. Septa rather 
numerous, the sutures strongly and abruptly bent back on the 
margin of the umbilicus, very slightly concave on the sides and 
nearly straight on the periphery. Siphuncle situated below the 
centre of the septa. Body-chamber probably very large. Test un- 
known. Casts quite smooth. 
llemarks. The author of this species observes that he has only 
met with fragments of it, which are rare in the ‘‘ craie jaune gros- 
siere ’’ of Saint-Pierre and Fauquemont h Comparing the present 
species with Nautilus ^owerbyanus, its nearest ally, it is found to be 
much more inflated, especially on the sides, which are distinctly 
flattened in N. Sowerbyanus. The two forms, however, resemble 
each other in the narrowly rounded periphery and small umbilicus. 
It should bo added that N. Sowerhyanus is from a much lower 
horizon (Chalk Marl) than N. Heberti. 
The only specimen in the Collection (No. C. 3359) gives the 
^ Saint-Pierre and Fauquemont are both situated in the Province of Lim- 
bourg, Belgium. 
