. Annals of the Carnegie Museum. Carnegie Museum; Carnegie Museum of Natural History; Natural history. 322 Annals of the Carnegie Museum. with fine crenulations. It is denned on the inner side by a narrow stripe of black pigment. In the male this lamella is also present, but much weaker. Farther in front the edge of the mantle is smooth. Palpi small, normal, their posterior margins connected only at the base. Gills short and broad, the inner ones broader. Diaphragm normal. Inner lamina of inner gills entirely connected with abdominal sac. Anterior attachment of gills as usual. Septa and water-
. Annals of the Carnegie Museum. Carnegie Museum; Carnegie Museum of Natural History; Natural history. 322 Annals of the Carnegie Museum. with fine crenulations. It is denned on the inner side by a narrow stripe of black pigment. In the male this lamella is also present, but much weaker. Farther in front the edge of the mantle is smooth. Palpi small, normal, their posterior margins connected only at the base. Gills short and broad, the inner ones broader. Diaphragm normal. Inner lamina of inner gills entirely connected with abdominal sac. Anterior attachment of gills as usual. Septa and water-tubes in both gills normally developed. Mar- supium restricted to a small section in the posterior half of the outer gill, leaving more than half of the anterior portion and a small posterior section non-marsupial. Ovisacs fifteeen to twenty (in my specimens); when charged not narrower than the normal water-tubes in the longi- tudinal direction, but expanding in the transverse direction, so that their lumen becomes lanceolate and compressed, the whole mar- supium thus appearing swollen and kidney-shaped. The marsupium extends considerably beyond the original edge of the gill, and about three-fourths of the length of the ovisacs is within the laminae of the. Fig. 20. Obovaria retusa (Lamarck). Gravid female, from Ohio River, Port- land, Meigs Co., O. (Cam. Mus., No. 61, ) gill, while one-fourth lies beyond the latter. Edge of marsupium blunt, without pigment. Placentae not well developed; eggs and glochidia rather loose. Glochidia rather large, suboval, without hooks. Length ; height mm. (see Plate XIX, fig. 9). Color of soft parts whitish, only edge of mantle brown, with a black streak in front of the branchial. Charged marsupium 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 Carneg
Size: 1919px × 1302px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., booka, bookcentury1900, bookdecade1910, booksubjectnaturalhistory
