THE STRUCTURE AND HABITS OF ARCHjEOPTERYX. 

 By C. H. Hurst, Ph.D. 



Plates XIV., XV., XVI. 



I. — The Skeleton of Arcileopteryx. 



Apart from a single feather, only two specimens of Archceopteryx 

 are known, and it is possible that these may not be identical in species 

 or even in genus. So far as we know them, the differences between 

 the two appear, to those who are best qualified to judge, to be too 

 small to justify separation into two species. Though both were found 

 in Bavaria, I shall refer to them as the "Berlin specimen" and the 

 "London specimen" respectively. 



It is not convenient to begin with a description of the external form 

 of the bird, as is customary with recent species, for that external 

 form can only be guessed at with reasonable chance of guessing accu- 

 rately after a careful consideration of the structure of such parts as 

 are still preserved. This is even more conspicuously true of the 

 habits of the animal. 



Of the skeleton, if we assume the two specimens to be so nearly 

 related that the characters exhibited in either may be taken as true of 

 both, we have quite an extensive knowledge. 



The vertebral column is readily divisible into four regions : cervical, 

 trunk, sacral, and caudal. Whether the vertebrae are fully ossified or not 

 it is difficult to say. I can find no justification for the statement that 

 they are amphicoelous. Professor Dames tells me that his statement 

 to that effect is a mere slip of the pen, and that he intended only to 

 say that, so far as can be seen in a specimen in which the vertebrae 

 are still in their natural relations with one another, the ends are flat 

 and not as in most birds, saddle-shaped. The central or internal part 

 of each vertebra in the London specimen is stated by Owen to be 

 represented by a deposit of crystalline "sparry matter" in the caudal 

 region, while the outer "crust" has adhered to the upper slab or 



