G. 0. Crick—Gigantic Cephalopod Mandible. 268 
the outer side the median line of the surface of the ‘hood’ makes 
amore or less obtuse angle with that of the surface of the ‘shaft’. 
The measurements of the detached calcareous portion of the upper 
mandible of a recent Nautilus pompilius figured by Dr. Till (1906, 
pL iy, figs. 1, 2, 3) are: total length, 14°5mm.; breadth, 10:1 mm. ; 
length of hood (measured along median line of outer side), 10°5 mm. ; 
length of shaft (measured along median line of outer side), 8°5 mm. ; 
angle between the hood and the shaft (measured along the median 
line of the outer side), 98°. Theangle of the apex of the hood as seen 
from the inner side is 82°. 
Fie. 2.—Nawutilus (Rhyncholithes butleri, n.sp.) sp. The type-specimen. 
a, outer aspect showing the obtuse ridge along the median line of the hood 
and at h remains of the chitinous portion of the mandible; b, lateral 
aspect, showing at p a series of shallow pits caused perhaps by a fringed 
lip, and at # remains of the chitinous portion of the mandible; c, inner 
view showing the median protuberance. Natural size. Most probably 
from the Inferior Oolite of Bradford Abbas (Dorset) or of the immediate 
neighbourhood. Original in British Museum (Nat. Hist.), London, Geol. 
Dept., No. C. 18659. é 
The present specimen is incomplete both at the apex and at the 
hinder end, so that only approximate measurements are possible. 
They are: extreme length, 51:7 mm.; breadth, 35:6 mm. ; length of 
hood (measuredalong the median line of the outer surface), 38-6 mm. ; 
length of shaft (measured along the median line of the outer 
