Published online by Cambridge University Press: 11 May 2009
These notes arise from the difficulty met with in identifying a pinkish encrusting sponge which has been frequently collected by hand from rocks at 5–10 fathoms. The sponge was at first identified, by a process of elimination, with the deep water genus Inflatella. Fortunately some preparations were shown to Dr Lévi at Roscoff to whom the species was at once familiar as Stylotella columella (Bowerbank). It was then found that this species had been described originally by Bowerbank from an Exmouth specimen, and subsequendy by Topsent from both south and west coasts of France. Topsent found the unusual, if not unique, character of this sponge in possessing, besides siliceous spicules, a great abundance of calcareous granules. These granules are almost certainly the ‘gemmules’ described and figured by Bowerbank. De Laubenfels in 1928 collected one specimen from Plymouth Sound which he identified as Stylotella columella; but proposed (1932) that the species should be included in the genus Prianos Gray. Burton in 1934 renamed the species Hemimycale columella, figuring the spicules as styles. Arndt (1935) returned to Stylotella and retained Burton's figure of the spicules. As the styles have been found, so far, only as a small minority amongst the spicules, it has been thought worth while to provide a further description; and to discuss the differing views on the systematic position of the species.