The two specimens figured below are from the collection of Mr. C. J. Read, of Salisbury, who obtained them from the Upper Chalk (Senonian) of the neighbourhood. Some uncertainty has attached to the exact locality, Mr. Read having told me that he had found them in the Mucronata-Chalk of Clarendon; but he now writes, 18th Jan. 1887—“My belief, on thinking the matter over, is that the right locality is the ‘Devizes Eoad,’ as they were originally marked.” The locality referred to is Old Camp Down lime-pit, three miles N.W. of Salisbury on the Devizes Road.