Silurian Uniserial Stomatoporæ and Ascodictya

Abstract

The genus Alecto was founded by Lamouroux in 1821 for a group of adherent Polyzoa. In 1814 Leach had used the word Alecto for a genus of Echinoderms; and Mr. Hincks says that it is still employed in connexion with the Crinoidea. On this account its further use for species of Polyzoa is objectionable. In 1825 Prof. Bronn used the word Stomatopora , and in 1826 Goldfuss used Aulopora , as names for individuals of the same genus as that founded by Lamouroux. For uniserial species d'Orbigny employed Prof. Bronn's name; but Blainville, Johnston, Milne-Edwards, Busk, and Defrance used the original word “ Alecto ” for species described by them in their various writings. The generic characters of Stomatopora have been given by various authors ; and additions have been made from time to time. The rather full description given by Goldfuss of Aulopora dichotoma ,together with figures of the species, renders identification comparatively easy. But somehow there has been a confusion in later identifications, and the Aulopora intermedia † type of Münster has been mixed up with Goldfuss's type. Both of these are present inthe Jurassic formation; and it is, I will admit, rather a difficultmatter to say where the one ends and the other begins. If, however, authors would distinguish between the two types, we should be able to get at the true range of the species, because each has an individual facies of its own. Hall, in describing the species foundin the Trenton Limestone of Americas (Trenton Falls, Oneida county), makes this distinction:—