128 EXTINCT MONSTERS. 



In order to give rapid movement to their wings during flight, 

 they had powerful muscles in the region of the chest. These 

 were attached to a shield-like breast-bone provided with a keel- 

 as in birds. But this bird-like feature is only a necessary pro- 

 vision to enable them to fly, and does not point to any relation- 

 ship. 



In the year 1873 was discovered, in the lithographic stone of 

 Bavaria, at Eichstadt, a very beautiful new form of Pterodactyl. 

 This was the Rhamphorhynchus phyllurus. The specimen is in a 

 remarkable state of preservation ; for the bones of the skeleton 

 are nearly all in position, while those of both wings show very 

 perfect impressions of the membranes attached to them. Its 

 long tail supported another small leaf-like membrane, which was 

 evidently used as a rudder in flight (see Fig. 35). The dis- 



FlG. 35. Skeleton of Rhamphorhynchus phyllurus, with delicate impressions of 

 the flying membranes. (After Marsh.) 



covery of this valuable specimen attracted much attention at 

 the time. It was bought, by telegram, for Professor Marsh, and 

 so secured for the Yale College Museum ; but a cast may be 

 seen at South Kensington (Wall-case, No. i, Gallery IV. on plan). 

 Any one who looks carefully at the beautiful impressions of the 

 wings of this specimen can see that they must have been produced 

 by a thin smooth membrane, very similar to that of bats. When 



