. Annals of the Carnegie Museum. Carnegie Museum; Carnegie Museum of Natural History; Natural history. Fig. 6. Stropheodonia ina-quistriata (Conrad). Neutral muscle area and ridges of an individual in later neanic or ephebic stages. X 2. Fic. 7. The same species. The corresponding area in ventral valve of a s]-)eci- men in later ephebic or gerontic stages. X 2. Fli;. 8. The same species. Interior of the dorsal valve of a young specimen, showing cardinal process and ridges in front of it. X 2. Fic,. 9. The same species. Interior of the dorsal valve of an adult, showing the two pairs of adductor
. Annals of the Carnegie Museum. Carnegie Museum; Carnegie Museum of Natural History; Natural history. Fig. 6. Stropheodonia ina-quistriata (Conrad). Neutral muscle area and ridges of an individual in later neanic or ephebic stages. X 2. Fic. 7. The same species. The corresponding area in ventral valve of a s]-)eci- men in later ephebic or gerontic stages. X 2. Fli;. 8. The same species. Interior of the dorsal valve of a young specimen, showing cardinal process and ridges in front of it. X 2. Fic,. 9. The same species. Interior of the dorsal valve of an adult, showing the two pairs of adductor muscle scars and the brachial ridges in front of them. X 2. Figs. 6-9 are from specimens in the writer's collection. borders of the diductor impressions send off processes a short dis- tance in front of the hinge which turn inward and run parallel for a short distance-. They rise sharply from the floor of the valve and overhang on the side toward the median line. In the later ne- anic stages the whole extent of the diductor impressions is bordered by a long sharp ridge which is later resorbed. During the adult stage, the parallel portions of the two ridges which bound the diductors are extended and strengthened, and the divergent portion is resorbed. The median ridge becomes stronger and rounded, the two sharp ridges which separated the adductors from the diductors disappear, and an almost square muscle scar is pro- duced. In this scar the diductors are very plain, and the adductors are narrow and situated somewhat posteriorly. Behind these is a median pedicle muscle (Fig. 7).. 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 Carnegie Museum; Carnegie Museum of Natural History. [Pittsburgh] : Published by authority of the Board of Trustees of the Carnegie Institute
Size: 2493px × 1003px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., booka, bookcentury1900, bookdecade1900, booksubjectnaturalhistory
