Published online by Cambridge University Press: 01 May 2009
As in the previous notes (Geol. Mag. Decade II. Vol. VII. No. 10, p. 447, 1880), so in the present, it is deemed desirable to give in the first instance a complete list of all the examples of the groups under consideration, which have hitherto been recorded, and then, having examined each critically, finally to give a corrected list.