12 BRITISH TUNICATA. 



rows around a common [excretory] orifice ; usually 

 forming a single system (fig. 92) but sometimes 

 two or more. Branchial aperture prominent, cut 

 into six triangular segments below which in each 

 individual are four rose-coloured [eye-like] spots. 

 Thorax pale. Branchial sac with ten rows of meshes. 

 bright yellow or orange, areolated. Post- 



aldomen long and slender. 



FIG. 92. Amaroucium argus. About five times natural size. (M. 



Edwards, pi. i, f. 4 a.) 



Height of mass half to three-quarters of an inch 

 (12 to 19mm.). 



Hob. On rocks and stones near low water-mark. 



ENGLAND. Salcombe Bay, Devon (HincJcs). Pol- 

 perro (Langhrin [1866]) and Falmouth (Alder [and 

 Codes']), Cornwall. Isle of Man (Alder). 



CHANNKL ISLANDS. Guernsey (Alder). 



First record. Forbes & Hanley, 1848 ; [coll. Alder]. 



This species appears to be nearly confined to our 



