154 
NAUTILOIDEA. 
sider the typical form of the species here described, has the periphery 
very depressed convex, while in the other it is distinctly more 
convex, or rounded. As they agree, however, apparently almost 
exactly in all other known characters, and both forms seem to vary 
somewhat in the convexity of the peripher}-, we are inclined to view 
them as merely varieties, or probably the different sexes of one 
species. In the more convex form the lateral nodes seem to be 
generally a little more inclined to become slightly elongated in the 
direction of the transverse diameter of the whorls, though this 
character appears not to be entirely constant. In both forms the 
longitudinal or revolving surface-ridges and furrows become nearly 
or quite obsolete toward the aperture on the body- whorl.” {Meeh 
and Worthen.) 
Remarlcs. The most remarkable feature in this species is the 
longitudinal ridges which ornament the shell. Professor Hyatt 
evidently regards this sculpture as possibly indicating affinities with 
Gyroceras^ for he places the present species in the same genus 
Q'’ Ko]jliinoceras”) as Gyroceras ornatum^ d’Arch. & de Yern., 
though he is rather guarded in his expression of opinion as to its 
place in the series, for he only says it is “ probably in this genus ” 
(“ Kopliinoceras ”). 
The longitudinal costae of this species separate it from aU others 
which may resemble it in other respects. 
Horizon. St. Louis Limestone (Lower Carboniferous). 
Locality. Putnam County, Indiana. 
Represented in the Collection by three or four very small speci- 
mens partly imbedded in matrix. 
Temnocheilus Goliathus, Waagen, sp. 
1879. Nautilus Goliathus, Waagen, Mem. Geol. Surv. India — Palaeont. 
Indica — ser. xiii., Salt-Range Fossils, vol. i. Productus-Limestone 
Fossils, p. 50, pi. iv., and Suppl. p. 85. 
Char. “ This species is represented by a sin'gle complete speci- 
men and a small fragment, but as its form is very characteristic and 
its geological position weR ascertained, it can well be described 
under a proper specific designation. 
“ The general form of the shell is that of a very thick disk. The 
umbilicus is very deep, but not very wide ; the whorls are very thick 
and inflated, with an extremely broad flattened external part [peri- 
phery]. The transverse section of the whorls is broad trapezoidal, 
the broadest diameter being near the outer edge of the whorl. The 
lateral parts [sides] of the whorls unite with the external part 
