The Scaphites have a singular boat-shaped form, wound with contiguous whorls in one part, which is detached at the last chamber, and projects in a more or less elongated condition.
Fig. 132.—Hamites. One-third natural size.
Hamites, Crioceras, and Ancyloceras have club-like terminations at both extremities; they may almost be considered as non-involuted Ammonites with the spiral evolutions disconnected or partially unrolled, as in the engraving ([Figs. 125] and [132]). Ancyloceras Matheronianus seems to have had spines projecting from the ridge of each of the convolutions.
Fig. 133.—Shell of Turritella terebra.
(Living form.)
The Toxoceras had the shell also curved, and not spiral.
The Baculites had the shell differing from all Cephalopods, inasmuch as it was elongated, conical, perfectly straight, sometimes very slender, and tapering to a point.