This paper was commenced over a year ago as a joint paper in collaboration with the late W. L. May, but was laid aside owing to the untimely death of Mr. May, whereby the Writer has lost his greatest friend, who was his colleague on so many collecting trips, and Science has lost a conchologist of outstanding ability. The earlier part of the paper records the results of a collecting trip to the north-western corner of the State.The party consisted of W. L. May, Watson Coleman, Miss Ashby, and the writer. The 28th and 29th October, 1924, were spent at Robbins Island and the 30th and 31st at Penguin. The discovery of representatives of the two genera, Stenochiton and Lepidopleurus, new to the State is of particular interest. Incl...