126 
NAUTILOIDEA. 
Carina; arc less prominent. Our s[>ecimcn Ixing merely a ca^t. we 
have no means of determining how near these two forms may have 
agreed in the details of their surface-markings.” 
The American examples of this species were obtained at Kockford, 
Indiana, in the Goniatites beds of the Kinderhook Group ( Ix)wer 
Carboniferous), and are associated, as at Tournai, with GoniatlUs 
rotatorim^ de Kon. ( = G. Ixion, Hall). 
The prominent raised band upon the periphery clearly sejjarates 
this species from any which it resembles in other respects. 
Horizon. Calcaire noir de Tournai (Assize i. €), = Carlx>nifen>ii." 
Limestone. 
Locality. Tournai, Belgium. 
lleprcsented in the Collection by two examjdes. 
Coelo nautilus gradus*, Foord. 
Fig. lb. 
CodonMitihis gradiis — a, lateral view of a nearly perfect specimen, showing tlie 
large central perforation ; h, outline of a polished section of another in- 
dividual showing the septa and siphuncle, and nearly the whole of the 
body-chamber; c, part of the periphery of another specimen, showing tlie 
longitudinal ridges. Drawn from specimens in the Collection. All of the 
natural size. 
Char. Shell thick, discoid, composed of about two and a half 
or three whorls, only just touching, and aU exposed in a deep, stei>- 
Expressive of the step-like form of the umbilicus. 
