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Isonema depressum

Gastropoda - Euomphalina - Anomphalidae

Synonyms
Synonymy list
YearName and author
1866Isonema depressum Meek and Worthen
1871Isonema humilis Meek pp. 79 - 80 figs. pl. 19 f. 1a-c
1873Naticopsis (Isonema) humilis Meek p. 214 figs. pl. 19 f. 1a-c
1909Naticopsis (Isonema) humilis Kindle p. 35 figs. pl. 10 f. 9
1909Isonema humile Stauffer p. 68
1963Isonema humile Bass and Northrop

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RankNameAuthor
kingdomAnimalia()
Bilateria
EubilateriaAx 1987
Protostomia
Spiralia
Schizocoela
phylumMollusca
RankNameAuthor
classGastropodaCuvier 1797
subclassEogastropoda
orderEuomphalina
superfamilyEuomphaloidea()
familyAnomphalidae
genusIsonema
speciesdepressum

If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.

Diagnosis
ReferenceDiagnosis
F. B. Meek 1871 (Isonema humilis)Shell large and robust, depressed subturbinate, about onefourth to near one-third wider than high; spire much depressed; volutions four, increasing rather rapidly in size, the exposed part of those of the spire gently convex; last one large and regularly rounded, or sometimes very obtusely subangular around the middle of the outer side; suture well defined, without being properly channelled; aperture circular a little within, but more or less angular above at the immediate edge of the lip, where it is more oval in outline; outer lip thin, and, in mature specimens, slightly dilated ; inner lip thickened, very distinctly flattened, and slightly spread over the imperforate umbilical region, as well as a little thickened near the top of the aperture. Surface ornamented with oblique, slightly arched lines of growth, which, on the first and second turns of the spire, are rather coarse, well defined, and present the characteristic regularity of size and arrangement, but soon become, on the succeeding turns, much finer and more crowded, as well as occasionally interrupted by irregular, stronger furrows and wrinkles of growth.