28 



BRITISH TUNICATA. 



Colony knob-like or pear-shaped, smooth, gelatinous, 

 pellucid, of a straw-yellow colour tinted with brown 

 and marked with whitish streaks from the immersed 

 animals ; adherent by abroad base (fig. 100, A). Indi- 



FIG. 100. Aplidium mitans. (After Johnston, loc. fit.) A, a group, 

 natural size. B, a single individual, x about 20. a, branchial 

 aperture ; b, branchial sac ; c, atrial aperture ; d, stomach (?). 



victuals irregularly scattered, and lying horizontally 

 or nearly so, with a short, bulging thorax, [a very 

 short abdomen,] and a long, linear post-abdomen (fig. 

 100, B). Stomach orange-coloured, marked with longi- 

 tudinal lines. 



