402 Scientific Proceedings, Royal Dublin Society. 



more numerous. Scapus, opaque when contracted, translucent 

 when fully distended ; flesh- or almost salmon-colour, sometimes 

 very sparsely, usually considerably splashed with reddish-brown 

 in irregular longitudinal lines, often interrupted, and ending in 

 streaks ; some specimens incline to brownish tinge, others chestnut, 

 and some are pinkish. Physa, translucent when expanded, tinted 

 with the ground colour of the scapus. Throughout the whole 

 colunm the insertions of the mesenteries appear as white lines, 

 which are, however, indistinguishable in the contracted scapus ; 

 posteriorly their number is increased by the occurrence of inter- 

 mediate ones. Tentacles translucent, pinkish, or very pale purplish- 

 brown ; at the base is a white W mark ; above this a white equi- 

 limbed cross, of which the arms are curved upwards. The space be- 

 tween these two markings is filled up with dark-brown ; above are 

 two white W marks, and frequently a third, but more faint and 

 imperfect. The lateral bays of these W marks are occupied by a 

 brown stripe, and are the only apparent markings under certain 

 aspects of the tentacles — sometimes a whitish streak may be detected 

 near the tip. The back of each tentacle bears an opaque white 

 spot about half way between the base and the tip. Disc pinkish, 

 with white inter-radial lines ; in the radii, at the lips of the mouth, 

 is a white spot ; above that a triangular brown spot ; outside this 

 a white A mark, and between this and the W at the base of the 

 tentacles is a brown )(, or hour-glass mark. Inside of oesophagus, 

 marked with twelve dark-brown bands, alternated with broader 

 orange-bufE bands ; deeper down the colour is reddish or purple. 

 Conchula flesh-coloured, or pale pink ; aperture appears black ; 

 lobes with a brown or dark-red core, usually with a white apical 

 spot, which may be prolonged into a white line, which appears to 

 connect the papillae with one another. 



The markings on the disk and tentacles vary greatly in form 

 and intensity, according to the degree to which the animal may be 

 distended. 



Dimensions. — Length, 1 to 4 inches (25 to 100 mm.) when 

 contracted; may reach 8 inches (205 mm.) when fully distended; 

 diameter about |-inch (12 mm.) whether contracted or distended. 



Habitat. — In sand at extreme low water, and at shallow depths. 

 Localities, N. France, S. England, E. Ireland, and E. Scotland. 



The appearance of the conchula has not been described by 



