. Smithsonian miscellaneous collections . at the dorsal furrow which he identifies as an appendi-fer. (Slide No. 153, M. C. Z.) See fig. 5, pi. 98. 12. (X S-) Longitudinal section of an enrolled trilobite in which the exopodites have been displaced and cut across at vary-ing angles so as to show the almost round transverse sectionwith a dark spot indicating that the muddy matrix had beenforced into some of the joints of the endopodite. (SlideNo. 200, M. C. Z.)14. () Transverse section of an enrolled specimen cuttingobliquely through the head, hypostoma and almost verti-cally through a thor
. Smithsonian miscellaneous collections . at the dorsal furrow which he identifies as an appendi-fer. (Slide No. 153, M. C. Z.) See fig. 5, pi. 98. 12. (X S-) Longitudinal section of an enrolled trilobite in which the exopodites have been displaced and cut across at vary-ing angles so as to show the almost round transverse sectionwith a dark spot indicating that the muddy matrix had beenforced into some of the joints of the endopodite. (SlideNo. 200, M. C. Z.)14. () Transverse section of an enrolled specimen cuttingobliquely through the head, hypostoma and almost verti-cally through a thoracic segment and the articular extensionof a mesotergite of another segment which forms a narrowdark crescent in the axial lobe. The important feature ofthe section is the series of round and broadly oval sectionsof the thoracic endopodites. Faint traces of exopoditesoccur in the lower portion of the figure. (Slide No. 20, Z.) Illustrated by Walcott 1881, pi. 2, fig. 10. SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 7, PL. 103. SECTIONS OF TRILOBITES NO. 7 NOTES ON STRUCTURE OF NEOLENUS 453 PAGEFig. 15. (X7-) Longitudinal section cutting across seven displacedthoracic endopodites. The four posterior have indicationsof joints and fine spines at the distal end of each. A frag-ment of the dorsal test of the pygidium is cut across inthe lower left corner. (Slide No. 63381, U. S. N. M.) Calymene meeki Foerste 453 Fig. 13. (X 5-5) Longitudinal section similar to that represented by fig. 12, to illustrate the similarity of the endopodites of this species from Ohio with the Central New York species. (Slide No. 68382, U. S. N. M.) The sections represented by figures 1-15 were made by me and are now in the Museum of Comparative Zoology at Harvard College, Cambridge, Massachusetts, with the exception of fig. 13. The sections are of trilobites from the Ordovician : upper portionof the Trenton limestone; 1 mile ( km.) east of the middle fallof Trenton Falls, on the West Canada
Size: 1279px × 1955px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorsm, bookcentury1800, bookdecade1860, booksubjectscience
