122 BRITISH TUNICATA. 



of the individuals being unattached. As this character, 

 however, is not borne out by any structural difference, 

 and is also found in some species of other genera, we 

 have not thought it desirable to consider it of generic 

 value. 



14. Styela vestita (Alder). 



(PL XXXVII, fig. 15 ; PI. XXXIX, fig. 9; PI. XLIII, 



figs. 4 and 5 ; PL XL VIII, fig. 17 ; and figs. 

 72-76 in text.) 



Cynthia vestita (Alder) STANGER in Trans. Tyneside Nat. 

 Field Club, IV [1860], p. 335; [ALDER in Nat. Hist, 

 Trans. NorthumbfDurh. I (1865), pp. 6, 11]. 



Cynthia glacialis ALDER in Ann. Nat. Hist. (3) XI [1863], 

 p. 164. 



v 



| 



s. 



o -.-- 



FIG. 73. Test of Styela vestita, devoid of shell fragments, and with 

 the apertures retracted. Four times natiiral size. 



Body orbicular or ovate, a little compressed, un- 

 attached, and [almost] entirely covered with sand 

 and fragments of shells. Apertures approximated and 

 slightly tubular when expanded, inconspicuous when 

 withdrawn, of a dull semitransparent white. Test 

 (PL XXXVII, fig. 15, and fig. 73 in text) smooth, 



