_Belodon_, _39_, 211; frontals, 277; palate, 281; vertebrae, 275 Bichir, _33_; see _Polypterus_ Bicipital groove, dog, 405 Bilophodont, defined, 345; teeth of Tapiridae, 429 _Bipes_, _38_; limbs, 289 Birds, anterior limb, 338; endoskeleton, 331 f.; exoskeleton, 328 f.; general characters, 295; hyoid, 336; pectoral girdle, 336; pelvic girdle, 339; posterior limb, 341; ribs, 336; skull, 333; sternum, 336; teeth, 330; vertebral, 332 _Bison_, _46_; occipital crest, 468 Blind snake, _38_; see _Typhlops_ Blind worm, _38_; see _Anguis_ Boidae, _38_ _Bombinator_, _36_; vertebrae, 172 Bone, development of, 10 f. Bone cells, 10 Bony Ganoids, fins, 105; pelvic fin, 132; ribs, 126; skull, 123; vertebral column, 114; see _Holostei_ Border: alveolar --, of dog's jaw, 398; coracoid, glenoid, and suprascapular -- of dog's scapula, 405 _Bos_, _46_; occipital crest, 468; ribs, 491; see Ox Bottlenose, _44_; see _Hyperoödon_ Bovidae, _46_; pes, 523; skull, 468 Bow-fin, _33_; see _Amia_ Brachial ossicles, cod, 103 Brachium; see upper arm Brachydont, defined, 345; teeth of Ungulates, 429 f. _Brachycephalus_, _36_; bony plates of, 168 Brain case, crocodile, 245; dog, 384; duck, 314; frog, 154; newt, 140; turtle, 224 Bradypodidae, _43_; see Sloths _Bradypus_, _43_; cervical vertebrae, 443; pectoral girdle, 495; skull, 457; thoraco-lumbar vertebrae, 447 Branchial arches, Amphibia, 180 f.; cod, 101; dogfish, 78; fish, 120 f.; newt, 145; salmon, 95; -- basket, Marsipobranchii, 38; -- skeleton, _Amphioxus_, 52; Balanoglossus, 50 _Branchiosaurus_, _35_; branchial arches, 180 Branchiostegal rays, cod, 100 _Brontops_, _46_; see _Titanotherium_ _Brontosaurus_, _38_, _207_; sternum, 288 _Bubalus_, _46_; ribs, 491; see Buffalo Buccal skeleton, _Amphioxus_, 52 _Buceros_, _42_; see Hornbill Buckler, of Labyrinthodonts, 168, 184 Buffalo, _46_; Cape --, skeleton of, =492= _Bufo_, _36_; hyoid, 182; jaws, 169; _B. viridis_, carpus, 186 Bufonidae, _36_ Bunodont, defined, 345; teeth of Ungulata, 427 f. Buno-selenodont, defined, 432 Caeciliidae, _35_ _Caiman_, _39_; _C. latirostris_ hyoid, =285=, limbs, =264=, lateral view of skull, =248=, palatal view of cranium and mandible, =245=, longitudinal section of skull, =253=, pectoral girdle, =262=, pelvic girdle and sacrum, =267=; _C. sclerops_, scutes, 271