Read December 6, 1814; and February 7, 1815.
I have the honour of submitting to the Linnean Society a sketch, showing the general construction with the extraordinary spiral and perhaps originally cartilaginous tubes of a certain division of the genus Anomia of Linnæus, or Terebratula of Lamarck. The Anomia striata of Martyn is represented at Fig. 2. (Tab. XXVIII.), having its triangular aperture between the beaks, which is characteristic of the division. In this species the side of the spiral tube is of a darker colour than the crystallized carbonate of lime which fills the shell, the whole being limestone. It is probable that these peculiar constructions may give characters to new genera, of which many species are found in England, France, Ireland, and even in New Holland, imbedded in limestone, flint, chert, or sandstone. In a specimen brought from New Holland by Mr. Brown, one only of the spiral tubes is to be seen; and it was not known positively that the shell ought to have two, until, a short time since, I discovered in my collection a complete specimen, from which Fig. 1. is taken.
