STAGE 66. Age +/- 58 d.

Ext. Crit.: *Border lines between adult skin areas disappeared*. *Tail only a very small triangle, no longer visible from ventral side*.

Int. Crit.: *Dorsal root of spinal gangl. 9 at level of gangl. 7*. Conjunctival sac formed.
*Plectral apparatus completed and operculum fen. ovalis confluent with wall of ear capsule; angle between palatoquadratum and anterior floor of cranium 115°*; formation of hyocricoid connection. Formation of adult m. levator mandibulae anterior and m. dpressor mandibulae; m. interhyoideus attached to palatoquadratum only. *Middle portions of ribs ossified*. *Tail only represented by small dorsal swelling of loose connective tissue, covered with degenerating larval skin*. Roofs of sternal pouches reduced. *Distal tarsalia ossifying*. Reorganization of mesonephros not yet competed.
*Dorsal coelomic sacs filled with lymphatic tissue; dorsal horns of lungs greatly reduced or absent*. Typhlosole disappeared; intestine making single loop*.