THE SESSILE BARNACLES. 351 



Platf 4G. 



Balnnus cnriosKS Pallas. Page 189. 



Fig. 1. Unalaska. Cat. No. 922G, U.S.N.M. Part of basal ed^P of lateral 

 C'ompavtmeut and rostrum. 

 2, 2rt. Unalaska. Cat. No. 48042, U.S.N.M. Lateral views of cylindric 

 specimens, the larger one deeply corroded. Natural size. 



3. Nazan Bay, Atka. Cat. No. 48045, U.S.N.M Young, natural size. 



4. Unalaska. Cat. No. 48043, U.S.N.M. Lateral view, natural size. 



Basal edge of same specimen shown in fig. 8. 



5. Neah Bay, Washington. Cat. No. 43044, U.S.N.M. Natural size. 



6. Unalaska. Cat. No. 922G, U.S.NM Colony of young specimens on 



a clam shell Natural size. 



7. Nazan Bay, Atka. Cat. No. 48045, U.S.N.M. Immature stage, not 



corroded. Natural size. 



8. Unalaska. Cat. No. 48043, U.S.N.]\L Part of the basal edge of 



the rostrum. 



9. Sanborn Harbor, Shumagin Islands. Cat. No. 3511, U.S.N.M. Two 



specimens which grew upon and in a sponge, part of which re- 

 mains on the right side, the rest removed to show the barnacles. 

 Natural size. 



Plate 47. 



Figs. 1-lc. Balanus cariosus (Pallas). Scutum and terguin of specimen from 



Unalaska. Page 189. 



Figs. 2-2(/. Balaniis! aciieas Lanchester. Scutum and terga of the type, and 



tergum of a paratype. Page 221. 



Plate 48. 



Figs. 1-1 f/. Balanus liairaiensis Pilsbry. Interior view of rostrum; interior 

 and outside views of tergum and scutum; an isolated individual, 

 and two groups. All enlarged. Page 222. 



2-2c. Balanus tantiUns Pilsbry. Interior and exterior views of the 

 opercular valves ; group on a sea-urchin spine, and more enlarged 

 view of three individuals of the same group. Page 224. 



Figures Ic, If/, 2c X 21 



