Descriptions of some New Species of Carboniferous Gasteropoda

Abstract

With one exception the Gasteropoda described in this paper have been collected by Mr. John Young, Hunterian Museum, Glasgow. The specimens are all very minute and are well preserved, their creamy colour giving them the appearance of shells of a much more recent date than the Carboniferous period. With the best of materials, however, the affinities of the Palæozoic Gasteropoda are always more or less difficult to determine. In this instance though the sculpture of the surface is wonderfully well preserved, none of the apertures are entire, and the minute size of the shells renders it difficult in many instances to discern the lines of growth. Out of the five Scottish shells three are undoubtedly Murchisoniæ, one in particular having the band indicating the sinus in the outer lip very clearly defined. With regard to the other two shells, I know of no genus to which they may be referred, unless it be Orthonema , Meek and Worthen. The more elongated shell bears some resemblance to species of the genus Aclisina , de Koninck, from which it differs, however, in the form of the mouth and the flattened, closely coiled whorls.