. Bulletin. Natural history; Natuurlijke historie. Text-figs. 58-61.—Transverse sections through patelloid shell. Explanation of symbols: a, angle between the general inner shell surface and the shell surface where the anterior mantle-at- tachment muscle is attached; eels, complex crossed-lamellar sublayer; m, myostracum; m -|- 1, m — 1, other shell layers; ps, prismatic sublayer. 58, all shell layers exposed on strongly eroded dorsal surface. 59, 60, relationship between angle of depositional surface and thickness of myostracum. 59, anterior mantle-attachment myostracum. 60, posterior part of
. Bulletin. Natural history; Natuurlijke historie. Text-figs. 58-61.—Transverse sections through patelloid shell. Explanation of symbols: a, angle between the general inner shell surface and the shell surface where the anterior mantle-at- tachment muscle is attached; eels, complex crossed-lamellar sublayer; m, myostracum; m -|- 1, m — 1, other shell layers; ps, prismatic sublayer. 58, all shell layers exposed on strongly eroded dorsal surface. 59, 60, relationship between angle of depositional surface and thickness of myostracum. 59, anterior mantle-attachment myostracum. 60, posterior part of pedal-retractor myostracum. 61, two kinds of shell sublayers in shell-layer m — 1. Further complications resulting from the lack of perfectly oriented sections in B0ggild's work can probably be traced to the already-discussed problem of the geometric relationship of first-order lamellae in the layer ventral to the myo- stracum. Some of the problems associated with interpreting shell-layer sequences also affected the work of Thiem (1917b), who used shell structures in his systematic descriptions of 12 acmaeid species. Thiem applied the term "ostracum" [Ostra- kum] to the outer shell layers and "hypostracum" [HypostraJnim] to the inner. 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 Peabody Museum of Natural History. New Haven : The Museum
Size: 3134px × 798px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionbiodiv, booksubjectnaturalhistory
