A Monograph on the Sub-class Cirripedia · Charles Darwin
PLATE 3.
_Genus_--BALANUS. Fig. 1 _a_, Balanus Ajax; 1 _b_, scutum external; 1 _c_, tergum external; and 1 _d_, scutum, internal view. 2 _a_, 2 _b_, Balanus stultus, scutum and tergum, external views; 2 _c_ and 2 _d_, scutum, internal and external views. 3 _a_, Balanus calceolus; 3 _b_, variety; 3 _c_, scutum, internal view; 3 _d_, tergum, internal view; 3 _e_, spur of tergum toothed. 4 _a_, Balanus galeatus; 4 _b_, 4 _c_, scutum and tergum, internal view. 5 _a_, 5 _b_, Balanus cymbiformis, scutum and tergum, internal view. 6 _a_, Balanus navicula; 6 _b_, 6 _c_, scutum and tergum, internal view; 6 _d_, scutum, external view. 7 _a_, Balanus trigonus; 7 _b_ and 7 _c_, scutum, external views, two varieties; 7 _d_, scutum, internal view; 7 _e_ and 7 _f_, tergum, external views, two varieties.
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