"Labtrinthoceras " is described as large, round-whorled with an open umbilicus; body chamber smooth with a terminal constriction.
22.
The upper and lower sides of the body chamber are essentially straight and virtually parallel, flaring slightly at the aperture.
23.
Tropitidae have subspherical to discoidal, involute to evolute shells with long body chambers and a ventral keel bordered by furrows.
24.
Many of these also have much or all of the original shell, as well as the complete body chamber, still intact.
25.
The first two possible ammonite egg specimens were found in sediments filling the interior of the body chambers of ammonite shells.
26.
The shell is fusiform in profile, reaching maximum width at or near the base of body chamber, which narrows toward the aperture.
27.
"Cranocephalites ", sometimes considered a subgenus of " Arctocephalites " which has sharply ribbed inner whorls and a smooth outer whorl, has a constricted eccentric body chamber.
28.
In early volutions whorl sections are rounded, but later develop an obtusely angular ventral area and venter that disappears toward the front of the mature body chamber.
29.
This would have been achieved by the endocones in the apical portion of the siphuncle that would have compensated for the visceral mass forward in the body chamber.
30.
"Gomphoceras ", named by Sowerby in 1839, is generally short but rapidly expanding, straight to slightly endogastric, with a gibbous body chamber such that all sides are convex.
