FOSSIL CIRRIPEDIA. 



bb, Balanus porcatus, small portion of basal margin of wall, much enlarged. 

 be, „ „ portion of basal plate, much enlarged. 



bd, be, bf, bg, Balanus porcatus, scutum and tergum, external and internal views ; 



engraved from recent specimens, the opercular 

 valves not having been positively found fossil. 

 Fig. 6a, Balanus crenatus, twice nat. size (Red Crag). 



6b, ,, „ small portion of basal margin of wall, much enlarged. 



6c, „ „ portion of basal plate, of unusual thickness, much enlarged. 



6d, 6e, „ „ scutum and tergum, external views from recent specimens. 



6f, 6g, „ „ „ „ war., internal views from recent specimens. 



Fig. la, lb, Balanus Hameri, scutum and tergum, external views engraved from Canada 



glacial specimens, the opercular valves not having been 

 found in Great Britain. 

 7c, Id, „ „ scutum and tergum, internal views of very large and old 



specimens (Canada and Uddevalla). 



