. Bulletins of American paleontology. 125 CiNCINNATIAN CePHALOPODS : FlOWER 43. - -J Figure 6. Structural details of nautiloid pliragmocoues. A. Portion of phragmocone sliowing wall of conrli, tlie septum, and cmniocting ring: (n) neck (b) brim (a) area of adnation. Note continuity of mural part of septum, free part of sei>tum and septal neck. B. Portion of a camera showing orthochoanitic septal neck, episcptal deposit (e) and hyposeptal deposit (h) in section. C. Portion of camera showing orthochoanitic sijTliuncle, with mural deposit in the camera. D. Aneuchoanitic siphuncle from SMdelero
. Bulletins of American paleontology. 125 CiNCINNATIAN CePHALOPODS : FlOWER 43. - -J Figure 6. Structural details of nautiloid pliragmocoues. A. Portion of phragmocone sliowing wall of conrli, tlie septum, and cmniocting ring: (n) neck (b) brim (a) area of adnation. Note continuity of mural part of septum, free part of sei>tum and septal neck. B. Portion of a camera showing orthochoanitic septal neck, episcptal deposit (e) and hyposeptal deposit (h) in section. C. Portion of camera showing orthochoanitic sijTliuncle, with mural deposit in the camera. D. Aneuchoanitic siphuncle from SMdeleroccras. E. Restored section through the dorsal wall of the pliragmocone showing the wall of the conch, the mural part of the septum, which is interrupted on the mid-dorsal area forming the septal furrow. (See also fig. 4.) F. Cyrtochoanitic septal neck of an actinoccroid rein- forced by the annulus. G. Cross section through a camera of a Pseu- dorlhneeras, showing circumferential variation in tlie cameral deposit, the ventral sinus, the ventrodateral masses, the dorsodateral bands, and the dorsal hiatus. H. Circumferential distribution of cameral deposits in Miclbelinoceras ludlowense. I. Cross section of a typical actinosiphonate siphuncle. J. Longitudinal section througli one side of a pseudorthoceroid siphuncle, showing the simple annulus adorally, while uejiosits farther apicad show successive growth stages of the parietal deposits to the point at which a continuous lining of the siphuncle is developed. taxonomic implication of the dichotomous division of ortho- choanitic and Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Paleontological Research Institution (Ithaca, N. Y. ); Columbia University. Ithaca, N. Y. , Paleontological Research Institution [etc. ]
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