. Bulletin - New York State Museum. Science. REPORT OF THE STATE PALEONTOLOGIST I903 311 ess formed portion of the endosiphocoleon as a free standing black and conchiolinous tube^ [see text fig. 15]. This shows that here the endosiphocoleon is not a mere continuation of the apex of the endo- siphocone, as it was found in Vagi noc eras belemniti- forme but a new formation, growing within the apical part of the visceral cone, presumably preparatory to a succeeding withdrawal of the animal from that part of the ^^^j^ siphuncle and the formation of a new endosiphosheath. Two sections which exhibit
. Bulletin - New York State Museum. Science. REPORT OF THE STATE PALEONTOLOGIST I903 311 ess formed portion of the endosiphocoleon as a free standing black and conchiolinous tube^ [see text fig. 15]. This shows that here the endosiphocoleon is not a mere continuation of the apex of the endo- siphocone, as it was found in Vagi noc eras belemniti- forme but a new formation, growing within the apical part of the visceral cone, presumably preparatory to a succeeding withdrawal of the animal from that part of the ^^^j^ siphuncle and the formation of a new endosiphosheath. Two sections which exhibit the same features are those reproduced in plate 7, figure i and plate 9, figure I. These possess on both narrow sides of the endosiphocoleon a series of two black concentric crescents which are not in contact with it. In some of these specimens [, ] the innermost of these crescents can be directly traced along the longitudinal sections to the strong conchiolinous wing or lat- ,€ral staff of the endosiphosheath I described above [sec text ]. Directly germane to the sections and diagrams given here and illus- itrative of the formation and charac- Iters of the wings of the endosi- phocoleon is the section in plate 8, figure 7. In this the apical part of the endosiphocone is transected land its semicircular outline shown in the center of the figure and its base, which corresponds to the flat or outer (ventral?) side of the siphuncle, is drawn out into short, obliquely ascending horns. The wall of the cone is formed by the endosiphosheath which is con- tinued in the direction of the horns to the wall of the siphuncle and ^It is twice as long as the lithographer's esJ) Fig. 15 Diagrammatic section of si- phuncle to show relation of endosiphoco- leon [^'jz-'] to endosiphocone [es^]. Endo- siphocone cut through minor axis: esl>, endosiphoblade; esc, endosipholining; ess, endosiphosheath. Please note that these images are extracted from scanned page i
Size: 1122px × 2227px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, booksubjectscience, bookyear1887
