Unpublished manuscript, 'Brief sketch of the anatomy of a new genus of pelagic Gasteropoda [sic] named Jasonilla' by John Denis MacDonald MacDonald describes a genus of pelagic Gastropoda, characterised, like Macgillivraya and Cheletropis, by the presence of ciliated cephalic appendages, but having a transparent, cartilaginous and symmetrical shell. MacDonald has seen one species, found between Port Jackson and the Isle of Pines [Australia]. Annotations in pencil throughout. Followed by one page of figures. Subject: Zoology Read 30 March 1855. Communicated by Sir William Burnett. Written by MacDonald at Sydney Harbour [Australia]. Whilst the Royal Society declined to publish this paper in full, an abstract of the paper was published in volume 7 of the Proceedings of the Royal Society as 'Brief sketch of the anatomy of a new genus of pelagic gasteropoda, named Jasonilla'. 10 December 1854