Bidder's organ, [49], [52]

Biedermann, on change of colour in Hyla, [35]

Birds not related to Dinosaurs, [416] f.

Bitis arietans, [639], [639];

B. nasicornis, [640]

Black Snake, of Australia, [634];

of North America, [613]

Blainville, de, on classification, [7]

Blanus cinereus, [566]

Blood, shape of red corpuscles, [4];