234 
XAUTILOIDEA. 
1884. Nautilus Calloviensis, Lahusen, Menioires du Comite Geologique 
[Eu&sia], vol. i. no. 1, p. 42, tab. iii. ff. 28, a, 6, and 29, a, b 
(young). 
1884. Nautilus hexagonus, Mallada, Boletin de la Comision del Mapa 
Geoldgico de Espana, vol. xi. Sinopsis de las Especies Fosiles de 
Espana, p. 229 (figured 1878, vol. v. pi. iv. f. 9). 
1890. Nautilus Calloviensis, Foord and G. C. Crick, Ann. Mag. Nat. 
Hist. ser. 6, vol. v. p. 289, f. 18. 
Fig. 55. 
Nautilus Calloviensis. — a, lateral view of a cast, showing the septation and part 
of the body-chamber; h, front view. Drawn fi-om a .specimen in the 
British Museum (No. 88979). Nearly two tliirds natural size. 
Sp. Char. “ General form of the shell somewhat compressed, 
smooth, or marked only by faint, very fine, close-set lines of growth. 
The whorls are obtusely angular, flattened at the sides, and broadly 
truncated upon the periphery, the greatest thickness being at the 
umbilical margin. The umbilicus is very small. The septa form a 
sigmoid curve upon the sides of the shell and are slightly sinuous 
upon the periphery. Siphuncle central. The ornaments of the 
test are described more exactly by Dr. Waagen ^ as follows : — 
‘ The shell itself is covered with two systems of flue striae, of which 
the parallel ones, which follow the direction of the spiral, are limited 
to the external part of the shell. The others — striae of growth — 
cover the whole shell, are somewhat falciform on the sides, but bend 
strongly backward on the external part. On very large specimens 
these lines become very strong and numerous, and look as if cnt in 
^ Mem. Geol. Surv. India — Palicont. ludica — Jurassic Fauna of Eutch, 
vol. i. p. 18. 
