 ... the umbilicus and the shape of the aperture are the same in both. But the principal distinction consists in the spiral lines which revolve on the whorl, intersecting the striae of growth, but so minute as hardly to be perceptible to the naked eye,...  Boston Journal of Natural History - Seite 4151841Vollansicht - Über dieses Buch
 | Amos Binney - 1851 - 390 Seiten
...as hardly to be perceptible to the naked eye, yet present in every specimen which I have examined. The whitish, narrow band, shaded below with rufous,...not so evident in this as in the preceding species. The rufous band below the white band, is well defined and broad, in a single specimen before me. 60.... | |
 | United States National Museum - 1885 - 984 Seiten
...as hardly to be perceptible to the naked eye, yet present in every specimen which I bave examined. The whitish, narrow band, shaded below with rufous,...Y"oung specimens are much more depressed than those of Z. ligerus, and are sometimes distinctly cariuated. The depression of the umbilical region is not so... | |
 | United States National Museum - 1885 - 594 Seiten
...as hardly to be perceptible to the naked eye, yet present in every specimen which 1 have examined. The whitish, narrow band, shaded below with rufous,...Young specimens are much more depressed than those of X. ligerm, and are sometimes distinctly carinated. The depression of the umbilical region is not so... | |
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