CEPHALOPODA OF THE CRETACEOUS MARLS. 273 
was coiled like the interior of a Scaphite or Ammonite, as I had one, having 
the septa of a Ptychoceras, which was so coiled, but which was destroyed 
accidentally before it could be figured. If I am correct in referring that 
specimen to one of the species of Ptychoceras, there described and figured (See 
p. 457, Pl. 16, Fig. 1), that one certainly would have been generically dis- 
tinct from the types of Ptychoceras and would probably prove congeneric 
with Dr. Morton’s species could better specimens be procured. Conse- 
quently I think it best to retain Mr. Conrad’s name for forms like that which 
I described and figured as above cited under the names Ptychoceras Meek- 
anum and P.crassum. In this case the generic diagnosis of Solenoceras would 
have to be changed somewhat as follows: 
SOLENOCERAS (as amended). 
Embryonic portions probably coiled forming one or more turns, beyond 
which the tube is deflected in a more or less direct line, or slightly bent to 
the end of the septate portion of the adult shell; terminal chamber recurved 
upon the septate portion, which it more or less embraces, the aperture may 
again be deflected from a right line where the younger parts are bent. 
Genus PTYCHOCERAS D’Orb.; Solenoceras Conrad. 
PTYCHOCERAS (SOLENOCERAS) ANNULIFER. 
Plate xLv, Figs. 6-8. 
Hamites annulifer Morton: Jour. Acad. Nat. Sci., Phila., Ist ser., vol. 8, p. 213, 
Pl. x1, Fig. £; Extract, p. 9, Pl. 1, Fig. 4. 
Solenoceras annulifer (Mort.) Conrad: Jour. Acad. Nat. Sci., Phila., 2d ser., vol. 
4, p. 284; Gabb, Synopsis, p. 33; Meek, Geol. Surv. N. J., 1868, p. 730. 
Ptychoceras (Solenoceras) annulifer (Morton) Meek: Check List Cret., p. 23. 
Shell small, known only from an internal cast of the chamber of habi- 
tation, which is rather less than a fourth of an inch in its greatest diameter, 
and only seven-eighths of an inch in length. The earlier portion of the 
shell appears to have been transversely elliptical in section, as it has left a 
broadly concave depressed area on the inner face of the outer chamber, 
which has a curvature very much greater than that of the outer face. Outer 
chamber contracted very slightly in diameter for a little more than the outer 
MON XVIII——18 
