On needles of rutile in the test of Bathysiphon argenteus

Abstract

Some years ago I was offered a few slides of foraminifera in exchange for a set of slides showing the dense minerals in the Hampstead Sands of which I had published an account. I made the exchange as one of the slides of foraminifera interested me very much. It was labelled ‶Bathysiphon? Earland Collection.″ I saw that the test contained large numbers of rutile needles, pointing to the habitat of the creature, which must be upon the surface of a disintegrating rutiliferous schist such as exists at Millport. I communicated with Mr Heron-Allen, an authority on foraminifera, who had kindly identified for me sundry Gromias and other foraminifera on which I had worked whilst they were alive, when at the seaside for the usual summer holiday. Mr Heron-Allen kindly sent me a copy of the Proceedings of the Royal Irish Academy, Vol. 31, where there was a description of Bathysiphon argenteus by Messrs Heron-Allen and Arthur Earland, from which it appears that the note of interrogation on Mr Earland’s slide had now been changed into ‶argenteus.″1 I think I cannot do better than quote what these gentlemen say about this interesting species at pp. 38-39 of their memoir. ‶Test free, minute, tabular, of a silvery lustre when viewed as an opaque object, flexible when living, rather brittle in a dry condition. Consisting of a very thin chitinous tube of nearly even diameter throughout but sometimes exhibiting a slight increase in diameter with growth. The tube is open at both extremities,