GEOLOGY. 275 



sion and counterpart in almost every instance. The feathered enigma 

 in question presents precisely similar appearances to all other in- 

 cluded organic remains, being imbedded upon the surface of one layer, 

 and impressed in intaglio into the one overlying it, which bears not 

 only the cast, but portions of the bones upon its surface. The fol- 

 lowing is a description of the remains, as they now exist in the British 

 Museum, for which it was purchased : The skull, neck, and both 

 hands are wanting, but all the dorsal vertebras belonging to the tail 

 are well preserved. The humerus and fore-arm, consisting of a radius 

 and ulna, are present on both sides. The pelvis, more like that of 

 a pterodactyl than a bird, is imperfect, the right side only remaining. 

 The thigh-bone is showy but not long, and the shank not perceptibly 

 divided into tibia and fibula. The tarsus consists of a single power- 

 ful bone shorter than the shank, and having its Iow6r extremity 

 widened, and bearing three articular processes to which as many toes 

 are attached. The latter are of moderate length, and armed with 

 strong hooked claws. These may have been used for clinging, like 

 those of the pterodactyls 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, and some others, are armed. 



The " merrythought," orfurculum, 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 ooh'tic sea. 



Except to the comparative anatomists, these singular remains might 

 present nothing striking, were not the anterior limbs and tail covered 

 with feathers, which have left their impressions in well-marked lines. 

 " From the-short, broad bone which lies close to the extremity of each 

 fore-arm there issues a radiating fan of feathers, by which two feath- 

 ered wings are produced, having their external outline curved like a 

 bow." The tail is also feathered, but the feathers are shorter than 

 those of the wings. 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 proportion to their size 

 from the body of the animal. 



The vertebrae of the tail are twenty in number, and are of a nar- 

 row, 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 arrange- 

 ments 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 last vertebra 

 very peculiarly formed, and, with few exceptions, alicays the largest. 

 To this last joint all the tail-feathers in living birds are attached, and 

 on it we find that peculiar oil-gland to which the bird applies its beak, 

 and so anoints and renders waterproof every feather of its body. 



Taking into consideration the remarkable divergence presented by 



