(STAGE 58-. Forelimbs in process of eruption, elbow piercing skin; angle of elbow about 90° and fingers folded in forelimb atrium.)

STAGE 58 Age +/- 44 d.; length 80-110 mm.

Ext. Crit.: *Forelimbs broken through*. Guanophores appearing on abdomen and thighs (adult skin areas). All three claws present on hindlimb.

Int. Crit.: *Metamorphosing skin of forelimb area caudally continuous with metmorphosing skin of trunk*. Saccus endolymphaticus extending down to 4^th spinal nerve.

*Appearance of maxillae; formation of septum and tectum nasi, crista intermedia, cartilago alaris and nasale*. Appearance of m. intermandibularis anterior. *Occipito-atlantal joint formed; 12^th pair of vertebral arches fused with 11^th and 10^th pairs*; *vertebrally and intervertebrally, chondrification of dorsal perichordal tube extending down to 10^th vertebra; hypochord chondrificed from 9^th to 12^th vertebra*. Appearance of m. rectus abdominis superficialis and paired m. sterno-hyoideus. *Melanin beginning to be deposited intercellularly in swollen epidermis of tail; tip of tail beginning to atrophy*. *Proc. epicoracoideus completely chondrified; scapula ossified perichondrally*; supra-scapula already much larger; *membane bones, cleithrum and clavicula formed*. *Last two carpalia chondrified, metacarpalia and phalanges ossified perichondrally*. Arm and hand musculature differentiated. *Left and right halves of pelvic girdle fused ventrally; ossification of ischia started*. *Only tarsalia and hallux purely cartilaginous, rest of hindlimb skeleton ossified perichondrally; single bony sheath of tibia-fibula*. In region of terminal phalanges muscles still in premuscular stage. Appearance of vena facialis. Pronephros no longer functional.

Goblet cells appearing in oro-pharyngeal cavity; *5-6 glandular ducts formed in intermaxillary glands*. *Extensive histolysis in duodenum*.