ON THE OSTEOLOGY OF NYCTOSAURUS (NYCTODAC- 

 TYLUS), WITH NOTES ON AMERICAN PTEROSAURS. 



BY SAMUEL W. WILLISTON. 



In previous papers* I have given a summary of the principal characters 

 of the genus Nyctosaurus,\ with more or less complete descriptions of cer- 

 tain parts of the skeleton. In the present paper I give a more detailed 

 description of the skeleton, based upon the unusually well-preserved and 

 nearly complete specimen collected by Mr. H. T. Martin, together "with 

 some remarks upon the relationships and habits of the American 

 pterosaurs, and the description of a new genus and species from the 

 Lower Cretaceous of Kansas. 



The specimen herewith described is of unusual importance, as throw- 

 ing much light upon the structure, not only of the American pterodactyls, 

 but also upon certain characters of the European ones. It is, I believe, 

 for purposes of study the most complete specimen of this order of reptiles 

 now known, comprising as it does nearly every bone in the skeleton, for 

 the most part associated in their natural relations. The specimen now 

 forms a part of the collections of the Field Columbian Museum. 



SKULL. 



A full description, with illustrations, of the skull has been given in the 

 Journal of Geology, vol. x, 1902, p. 520. I give herewith illustrations 

 of the mandible, not there figured. A careful measurement of the 

 sides of this bone a little in front of the posterior end of the symphysis, 

 where they are the broadest, obtained by measuring each fractured portion, 

 gives a width for each side of twenty-four millimeters. The correspond- 

 ing width of the palate is twenty-eight millimeters. This would give, as 

 the greatest depth of the mandible, near the end of the symphysis, 

 about twenty millimeters. 



♦Kansas University Quarterly, vol. i, p. 5, 1892. 



American Journal of Anatomy, vol. 1, p. 297, 1902. 



Journal of Geology, vol. x, p. 520, iqo2. 



Text Book of Paleontology, Zittel (Eastman), vol. ii, p. 255, f. 361. 



tThis genus has generally been known as Nyetodactylus. (See synonymy beyond.) Marsh 

 changed the name because of the supposed preoccupation of the name Nyctosaurus. In this he 

 was not justified. The name has never been used otherwise for a genus of animals. Doubtless he 

 thought the term conflicted with Nyctisauria, used for a group of sauria. It does not, however, 

 according to the accepted canons of nomenclature, and the original name should not be displaced. 



Field Col. Mus., Geol. Ser., Vol. II, No. 3. 



