318 On a Feathered Fossil. 



beside the radius and ulna; there are also some small detached 

 bones, which no doubt are finger bones. Above the wing 

 feathers on the left hand may be noticed two small slender 

 bones, to which sharp claws, similar to those of the foot, 

 are articulated. These may have been used for clinging, like 

 those of the pterodactyles and bats, or as offensive weapons, 

 like the fighting spur with which the wings of the spur- winged 

 goose of the Cape and Central Africa, the Chaja Screamer 

 (related to the Kails) from Cayenne, and some others are 

 armed. 



The "merrythought," ovfurculum, is seen lying between 

 the wings. The ribs, small and unbird-like, are detached, and 

 scattered on the surface, as if the head, neck, breast, and body 

 had been torn off or eaten out by some other bird of prey or 

 small carnivorous animal, wandering at low water upon the 

 estuarine flats bordering that ancient oolitic sea. 



The lower right limb is well preserved, and consists of femur, 

 tibia, and tarso-metatarsal bones ; to the latter bone four toes 

 are articulated, one hind toe and three fore toes, having seve- 

 rally 1, 2, 3, and (4 ?*) joints, as in all birds, and armed with 

 strong hooked claws. The thigh and shank only of the right 

 limb remain. The pelvis is well preserved on the left side, 

 showing the cup-shaped cavity in which the head of the femur 

 moved. f 



The sacrum (so conspicuous in all known birds) cannot be 

 traced in this skeleton, unless the stained surface of the stone 

 indicates its remains. That one existed by which a few at least 

 of the sacral vertebras were firmly fixed together may be fairly 

 concluded, for the hind limbs seem well adapted for hopping, 

 running, or perching; and the wings (which evidently were 

 adapted for flight) must also have received support in propor- 

 tion to their size from the body of the animal. 



The whole of the vertebras of the tail are completely and 

 beautifully preserved. They are twenty in number, of a narrow, 

 elongated form, the dimensions of which slowly but constantly 

 diminish, so that the last is the smallest. The feathers of the 

 tail are attached in pairs to each vertebra throughout its entire 

 length. It is in the form and number of the caudal vertebras, 

 and the arrangements of the tail feathers, that the great and 

 striking peculiarity of this remarkable creature lies. 



In all recent birds we find the tail very short and powerful, 

 composed of vertebras varying from five to nine in number, 

 having spinous processes on their upper and under side, and 



* The fourth, toe bones underlie the second and third, and cannot be certainly 

 counted. 



t The fossil is lying on its bade, so that we view the underside of its feathers 

 and bones. 



