Ox a Restoration of the Base of the Cranium of 

 HESPERORNIS REG A EI S 



By R. W. Shufeldt 



In -so far as I am aware, there has not, up to the present time, 

 been published a figure giving the probable appearance, and the 

 various bony parts, of the cranium of that great, extinct, loon- 

 like diver of Cretaceous times — Marsh's Hesperornis regalis. 

 Disregarding a text-cut on page 9 of the "Odontornithes," Marsh 

 gives us, on Plate I of that work, but two natural-size views of 

 the cranium of H. regalis which show the lost parts restored in 

 outline. These figures I have carefully studied and compared 

 with several skulls of the Loon ( Gavia immer ) , belonging to 

 the collection of the United States National Museum; further, 

 I have compared the former as well as the latter with a series of 

 photographs, sent me by Mr. Gerhard Heilmann, of Copenhagen, 

 which photographs were made of the cranium of the type speci- 

 men of H. regalis in the Peabody Museum of Yale University, 

 under the direction of Professor Richard S. Lull. These are help- 

 ful, in the absence of the actual specimen ; though not as much as 

 they might be had they been obtained by a photographer of ex- 

 perience. Unfortunately, no attention was paid to lighting, to 

 point of view, or to the matter of reproduction of detail, while 

 they show fairly well several other points. Lastly, to aid one 

 in restoring the base of the cranium of Hesperornis regalis, there 

 are to be found still other illustrations in the " Odontornithes." 

 We have, on Plate II of the work, no fewer than twelve figures 

 devoted to the teeth and osseous structures at the basis eranii; 

 these will be duly commented upon as they are taken up in detail 

 and associated in the restoration here to be made. 



Evidently, the first step to be undertaken is to obtain a 

 correct outline of the base of the cranium, as the details within 



