_Genus_--BALANUS.
Fig. 1 _a_, Balanus perforatus,--_var._ angustus.
1 _b_, " " " Cranchii.
1 _c_, " " " mirabilis.
1 _d_, " " " fistulosus.
2 _a_, " amphitrite,--_var._ venustus.
2 _b_, " " _var._ cirratus.
2 _c_, " " " pallidus.
2 _d_, " " " Stutchburii.
2 _e_, " " " communis.
2 _f_, " " " niveus.
2 _g_, " " " obscurus.
2 _h_, " " scutum, _var._ communis.
2 _i_, " " " " Stutchburii.
2 _k_, " " tergum, " pallidus.
2 _l_, " " " " communis.
2 _m_, 2 _n_, and 2 _o_," " _var._ Stutchburii.
3 _a_, Balanus pœcilus, scutum, internal view; 3 _b_, tergum,
external.
4 _a_, Balanus eburneus, scutum, external view; 4 _b_,
tergum, external; 4 _c_, scutum, internal; 4 _d_, tergum
(_var._), internal.