. Bulletin - New York State Museum. Science. Fig. 35 Fig. 36 Fig. 35 Scliroederoceras cassinense Whitf. (sp.) Transverse section. Natural size Fig. 36 Schroederoceras cassinense Whitf. (sp.) Enlargement (x ) of portion of longitudinal section, siiow- ing the structure of the siphuncle (siphuncular segments dotted) We have referred several specimens to this species rather than to S. eatoni on account of their straight sutures and the section of the ephebic volution, which possesses about equal transverse and dorsoventral diameters. In one specimen which we figure here the ventral and lateral
. Bulletin - New York State Museum. Science. Fig. 35 Fig. 36 Fig. 35 Scliroederoceras cassinense Whitf. (sp.) Transverse section. Natural size Fig. 36 Schroederoceras cassinense Whitf. (sp.) Enlargement (x ) of portion of longitudinal section, siiow- ing the structure of the siphuncle (siphuncular segments dotted) We have referred several specimens to this species rather than to S. eatoni on account of their straight sutures and the section of the ephebic volution, which possesses about equal transverse and dorsoventral diameters. In one specimen which we figure here the ventral and lateral faces are so strongly developed that very well marked abdominal angles on both sides of the ventral zone or abdomen are formed [sec pi. 20, fig. i]. A transverse section of the same specimen which is also figured here shows the char- acteristic low broad volution of the neanic stage and a higher whorl of the anephebic stage. A special interest attaches to another specimen, also here figured, on account of its retaining the finer details of the siphuncular struc- ture. The siphuncle which is propiodorsan in position exhibits very short straight septal necks [sec text fig. 36], which are not longer than about one eighth of the depth of the cameras, the siphuncle wall being formed almost entirely by the secondary siphuncular segments. Position and localities. At Fort Cassin Yt. and A^^ of the Fort Cassin beds at \^ 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 New York State Museum; New York State Museum. Albany : New York State Education Dept
Size: 1126px × 2219px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, booksubjectscience, bookyear1887
