33& 



Correspondence. \ ^ u 



LOct. 



the great similarity of a number of the skeletal characters as seen in 

 Sula brewsteri as compared with the corresponding ones of the genus 

 Phaethon. 



Again, in some osteological particulars Phaethon links the Stegano- 

 podes with the Longipennes on the one hand, and with the Tubinares on 

 the other. There are many suggestive "gull characters" in the skeleton 

 of Phaethon flavirostr is, and even more that suggest to us the skeleton as 

 seen in Puffitius. 



Of the three superfamilies given in my scheme above, the most unique 

 and best defined one is the Fregatoidea. The pelvis in Fregata is more 

 like the pelvis in Phaethon than it is like that bone in any of the other 

 steganopodous types, but the strangest fact is the very close resemblance, 

 both superficial and real, its skull has to the skull of a typical Albatross, — 

 as for example that of Diomedea albatrus. In my P. Z. S. article I 

 pointed out a number of these characters, but in another account not as 

 yet published, I have written out a very full comparative description of 

 the skeleton of Fregata which will appear in due course. 



Passing now to another matter I would invite your attention to 

 another paper recently published by the present writer, and I refer to my 

 'Comparative Oology of North American Birds' which appeared in the 

 Report of the U. S. National Museum for 1892. On page 461 of that 

 memoir I remark that I am "not aware of the discovery of the eggs of 

 any of the now extinct forms of reptiles, either fossil or subfossil, and it 

 is beyond all probability that we will ever know what the eggs of Archa?- 

 opteryx, or any of the toothed birds of the Kansas Cretaceous Beds 

 (Hesperornis, Ichthyomis, and others), or, indeed, any of the smaller 

 extinct types of Aves, looked like." This opinion I believe to be quite 

 general, or at least it is by no means a well-known fact that specimens of 

 fossil eggs of both reptiles and birds have been found and now exist in 

 certain collections. I was among the number standing in ignorance of 

 that fact when I published my above-named memoir, but since then, 

 through the kindness of Mr. F. A. Lucas of the U. S. National Museum, 

 I have been shown in the palseontological collections of that institution, 

 very perfect specimens of thoroughly fossilized eggs of a small turtle, 

 probably an Emys, also fairly good specimens of fossilized birds' eggs 

 (Larus, or of some allied type?). 



All these specimens are from the Paris Basin, and were received from 

 the distinguished French savant, M. Alphonse Milne-Edwards. The 

 birds' eggs, which interest us here, consist of a subfossilized, more 

 or less broken shell, of a dull gray color, which closely overlays the 

 solid fossil infiltrated matter that fills up in each case the egg cavity. 

 Those I examined show no evidence of markings of any kind on the 

 surface of the shell, which is no more than what we would expect. With 

 such specimens as these before me, I can now easily believe that it lays 

 quite within the range of possibility for us someday to find in the Kansas 

 Cretaceous Beds fossilized eggs of the extinct toothed birds above named. 



