. Annals of the Carnegie Museum. Carnegie Museum; Carnegie Museum of Natural History; Natural history. Ortmann: Families vnd Genera oi Najades. 233 Haas omitted to saj anything aboul the gill-structure, his description ol the margins of the mantle, of the diaphragm, and other parts renders it absolutely certain thai this species musl be placed in the family Margaritanida. Haas points oul certain differences from Mar- garitana margaritifera, of which the mosl importanl is the fact that the shell Ins lateral hinge-teeth. Since we have other genera among the Najades in which the hinge-teeth arc v
. Annals of the Carnegie Museum. Carnegie Museum; Carnegie Museum of Natural History; Natural history. Ortmann: Families vnd Genera oi Najades. 233 Haas omitted to saj anything aboul the gill-structure, his description ol the margins of the mantle, of the diaphragm, and other parts renders it absolutely certain thai this species musl be placed in the family Margaritanida. Haas points oul certain differences from Mar- garitana margaritifera, of which the mosl importanl is the fact that the shell Ins lateral hinge-teeth. Since we have other genera among the Najades in which the hinge-teeth arc variously developed, and since it is absolutely clear, thai Margaritana margaritifera, withoul lateral teeth, must have descended from forms with such teeth, I think the differences in Unio sinuatus should be regarded as only of specific value, and I see no reason why we should not place it with Margaritana, with which some of its most essential and importanl characters are known to agree, while all the known differences .ire such a- in other groups are known to be of minor value. Margaritana sinuata thus would represenl a somewhat more ancient type than .1/. margaritifera (see Ortmann, 1911c, p. 6). Margaritana monodonta (Say). I have received, from B. Walker, one complete specimen, and the soft parts of three others, all from the Cumberland River in Pulaski, Russell, and Cumberland Counties, ?t an Fig. 2. Margaritana monodonta (Say). Specimen from Cumberland River, Rowena, Russell Co., Ky. (Cam. Mus., No. 61, 4,960.) We may compare the description of the soft parts by Lea (Obs., X, 1863, p. 422), which, however, mentions among the important teat tires only the posterior end of the gills, the branchial and anal openings. Margins of the mantle, branchial and anal openings as in M. mar- garitifera. Xo supra-anal present. Posterior margins of palpi connected for about one-third of their length, ('.ills rather long (cor- responding to shape of shell), the inner the wider
Size: 2694px × 927px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., booka, bookcentury1900, bookdecade1910, booksubjectnaturalhistory
