100 MALONE JURASSIC FORMATION OF TEXAS. [bull. 266. 
When viewed from above, the cast presents a somewhat squared 
form, due apparently to the accident of rock pressure. 
CEPHALOPODA. 
NAUTILOIDEA. 
Genus NAUTILUS Breyn. 
Nautili s burkart] C. and A. ? 
PI. XXII, fig. 1. 
Nautilus burkarti Castillo and Aguilera, 1895, Bol. Com. Geol. Mex., No.l, 
p. 12, PI. XXI, tig. 3. 
I provisionally refer to this species an imperfect specimen of Nau- 
tilus of inflated form obtained by Doctor Stanton in No. 13 of his 
Malone Mountain section, on the west side of the mountain southwest 
of Malone station. The dimensions are much larger than those indi- 
cated by Castillo and Aguilera's figure and description of N. hurkartm 
which are perhaps those of a young example. 
The Malone Mountain specimen o-ivos the following measurements I 
Height of shell. 123 mm.; height of last whorl, 67 nun.; breadth of the 
latter, as restored, 86 nun. The height of the last whorl is therefore 
about 54.5 per cent and its breadth about 70 per cent of the height of 
the -hell, as against 55 and 64, given as corresponding percentages for 
the type-specimen. 
The following is a translation of the original description of the 
species: 
Shell extremely inflated; spire composed of few whorls which cover more 
than three-fourths of the whorls preceding; Hanks quite convex ami attaining 
their greatest thickness near the umbilicus, whence they descend gradual™ 
toward the siphonal region, which is quite rounded; umbilicus narrow, deep, 
and funnel-shaped; aperture very much invaded by the spire whorl, wider than 
high, rounded on the upper pari : surface nearly smooth, destitute of tubercles, 
hearing only marked growth lines, which make it slightly rough on some parts. 
Diameter A\). 00 mm. 
Breadth of the last whorl in relation to the diameter . ."> 
Thickness of the last whorl in relation to the diameter . 64 
Diameter of the umbilicus to the diameter .23 
Nautilus naufragus sp. n. 
PI. XXIII. fig. .'i. pi. xxiv, fig. 3. 
Shell involute, somewhat compressed: volutions deeply embracing, 
increasing rapidly in size, narrowed on the feebly convex flanks from 
