A single specimen of Oriostoma globosum (von Schlotheim, 1820) from the Silurian-age (Wenlockian) Laurel Limestone in southeastern Indiana preserves a partial, multispiral operculum in situ within the aperture. Only eight specimens of in situ Oriostoma opercula have previously been illustrated from Canada and Europe, and this is the first from the United States. Oriostoma huntingtonensis Kindle, 1904, from younger Silurian (Ludlovian–Pridolian) strata in northern Indiana is considered a synonym of the more widespread O. globosum, and it was described as having associated loose multispiral calcareous opercula in the same strata.

中文翻译：

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Oriostoma (Gastropoda) 具有来自印第安纳州志留纪的原位鳃盖

单个标本球形口虫(von Schlotheim, 1820) 来自印第安纳州东南部的志留纪（文洛克期）月桂石灰岩，在孔径内原位保留了一个部分的多螺旋鳃盖。仅8个原位标本口线虫鳃盖以前曾在加拿大和欧洲进行过插图，这是美国的第一个插图。亨廷顿口线虫Kindle，1904，来自印第安纳州北部较年轻的志留纪（Ludlovian-Pridolian）地层，被认为是更广泛的同义词O. globosum，并且它被描述为在同一地层​​中具有相关的松散的多螺旋钙质岛盖。