On the Genus Loxonema , with Descriptions of New Proterozoic Species

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Abstract
There is considerable confusion with regard to the genotype of Loxonema , Phillips. This has arisen because Phillips did not fix a genotype himself, and because he confounded a Devonian form with his first-mentioned species. This last is the Silurian Terebra (?) sinuosa of Sowerby? Both the Devonian form which Phillips calls Loxonema sinuosum and Sowerby's holotype bear the characteristics of the genus as defined by him, but they certainly are specifically distinct. The genus was founded by Phillips in 1841; and, though I have given the original diagnosis in a former paper, it seems advisable to reproduce it here :— ‘ Spiral, turriculated ; whorls convex, their upper edges adpressed against the next above; without spiral band; mouth oblong, attenuated above, effused below, with a sigmoidal edge to the right lip ; no umbilicus (?) ; surface covered by longitudinal threads or ridges, generally arched. ‘ These observations are merely provisional until the form of the aperture is more perfectly known. The shells have been placed as Melania , Rissoa , Terebra , Turritella , and Sealaria . ‘ In regard to the number of species mentioned, I must observe that I find it impossible to do otherwise than preserve the names of all as distinct varieties ; but that it is very probable most of them ,are only varieties of three or four types, one having L. sinuosa for one extremity and L. Hennahii for the other ; a second related to L. tumida and L. lineta ; a third to L. rugifera . Count Münster's

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