SPERMATOPHORES OF SIX EASTERN NORTH AMERICAN PYRAMIDELLID GASTROPODS AND THEIR SYSTEMATIC SIGNIFICANCE (WITH THE NEW GENUS<i>BOONEA</i>)

Abstract

1. Six east North American odostomioid species (Gastropoda: Pyramidellidae) are shown to have spermatophores that are species-specific in structure and position. The spermatophores of Boonea seminuda, B. bisuturalis and B. impressa are stuck in the mantle cavity; those of Fargoa dianthophila, F. bushiana and F. bartschi are attached to the shell in a constant position. 2. A supraspecific classification based on spermatophores does not accord with the traditional ones based on shell sculpture. By comparing all available lines of evidence, the spermatophore classification is shown to accord more closely with phyletic relationships. Shell sculpture has converged and diverged evolutionarily and is therefore unreliable in supraspecific pyramidellid systematics. With due allowances for variation it is, however, useful at the species level. 3. The new genus Boonea is named, based on spermatophore and other data, with "Odostomia" seminuda as type-species. 4. Reasons are given for using the name F. bartschi for "O. modesta" and F. bushiana for "O. dux" of authors.