1889 .] 
277 
[Foerste. 
men the two largest fragments probably belonged. The sides of 
the specimens are moderately convex, rounding regularly into the 
stronger convex inner portion of the coil, and more suddenly into 
the decidedly flattened, scarcely convex, outer part of the coil. 
The septa are moderately concave, forming an arc of about 103° 
in both the small specimen, the type, where the vertical diameter 
of the shell is 57 inm., and at the smaller end of the larger speci- 
men, probably the living chamber, where the vertical diameter of 
the shell was 70 mm. The siphon lies within two-fifths of the ver- 
tical diameter of the shell from the dorsal or outer side of the coil. 
The siphon is strongly nummulated, the annulse being 12 mm. in di- 
ameter where the shell has a vertical diameter of 60 mm. The an- 
nulations become regularly contracted towards the septa, the 
connecting aperture being 4 mm. in diameter. The fold formed by 
the contraction of the siphon at the septa bends back slightly into 
the previous annulation in each case, forming what might be de- 
scribed as a short flaring funnel with a wide aperture. The shell 
preserved on the type specimen is 1 mm. thick, and is marked 
by slightly concave spaces, readily seen, but not very distinctly 
differentiated, forming intersecting oblique rows across the shell, 
decreasing in size towards the inner side of the coil. These have 
something of the form but not the distinctness of the accompanying 
figure of the surface of the shell. When the diameter of these ir- 
regularly rhomboidal spaces, along the longitudinal axis of this part 
of the coil, is slightly increased, these spaces then have very much 
the form of Glyptodendron scars, but much smaller. Along the mid- 
dle of the side of the type specimen where the vertical diameter 
of the shell is 51 mm., there are five of these diagonal rows of rhom- 
boidal markings in a length of 11 mm., along either diagonal. In 
the larger specimen these markings are much more imperfectly 
preserved ; where the vertical diameter of the shell is 80 mm., five 
of these markings occupy a length of 18 mm. along either diago- 
nal. In case of the smaller type specimen, a few transverse striae 
are noticed crossing these rhomboids at one place near the um- 
bilical or inner side of the coil. The character of the surface mark- 
ings will readily distinguish this species from any other known to 
me. 
The living chamber of a large nautiloid shell in which the end of 
the aperture becomes free, bending back slightly from the coil at its 
