THE WING-FINGER OF PTERODACTYLS . 705 



an excised membrane would have been little better than none 

 at all. 



That the ribs of the abdominal region extended out into the 

 patagial membrane on the sides I have given reasons for elsewhere ; 

 I can see no other explanation for their position and lack of curva- 

 ture in the specimen of Nyctosaurus to which I have referred. 



