64 BRITISH TUNICATA. 



Ham'ock). [Selley's beach, Falmouth, Cornwall 



(Cocks).] 



First record. Alder & Hancock, 1848. 



This species is distinguished from the last by the 

 thinness of the general envelope, and by the smaller 

 size and variegated reddish colour of the individuals. 



A variety (PL LXI, figs, 3 and 4) is marbled with 

 red and has a yellow central line. 



3. Botryllus virescens Alder & Hancock. 

 (Plate LXI, figs. 8-11 ; and figs. 123 and 124 in text.) 



Botrylhis riiTNci'iix ALUKI; A: HANCOCK in Trans. Tyneside Nat. 

 Field Club, I [1848], p. 205; FORBES & HANLEY Brit. 

 Moll. II [1849], p. 370; [COCKS in Rep. R, Cornw. Polyt, 

 Soc. for 1849 (1850), p. 74]. 



Colony (PI. LXI, figs. 8 and D) incrusting, semi- 

 transparent, olive-brown in colour, sprinkled with 



FIG. 123. Botryllus virescens. Systems of from seven to eleven 

 individuals. Enlarged. 



yellow granules. Individuals grass-green, varying to 

 greenish-yellow and occasionally to pale grey ; the 

 colour generally confined to the lower and middle 

 portions of the animal, the upper part being so nearly 

 the colour of the enveloping mass (PL LXI, fig. 10) as 

 to be with difficulty distinguished from it. Branchial 

 aperture large with a faint red margin. Tentacular 



