26 Proceedings of the Royal Society of Victoria. 



Stage IT. — In the anterior limb the smaller process, indi- 

 cating the first digit, is still ver}'- distinct. A special series 

 of processes indicating feathers ai-e developed along the 

 post-axial border, and the third digit begins to become 

 indistinguishable. The arm lies parallel to the long axis of 

 the body, the forearm is bent forward at a sharp angle to 

 this, and the manus projects at right angles to the long axis 

 of the body. In the hind limb, the proximal part is covered 

 Avith long processes indicating feathers, the middle portion 

 with blunt processes, and the distal portion is developed 

 into a definite foot. 



Stage V. — The first digit loses its ])rominence, and the 

 third one has almost disappeared. The whole is covered 

 with developing feathers. In the hind limb, the middle as 

 well as proximal portion is covered with hair-like processes, 

 still longer than in the preceding stage. 



Stage W. — In the anterior limb the first digit can only 

 just be distinguished, and the limb has assumed a wing-like 

 form. In the hind limb the divisions are bent at sharp 

 angles upon one another, and the four digits have assumed 

 very much the adult condition. 



