0. C. Marsh— New sub-order of Pterosauria. 509 



Fteranodon comptm, sp. nov. 



The smallest Pterodactyle known from American strata is in- 

 dicated by portions of three skeletons in the Yale Museum. 

 Among these remains are two distal ends of the characteristic 

 metacarpal of the wing finger, other portions of the wing bones, 

 and two sacral vertebrae. The large metacarpal is very slender, 

 and elongated, and its outer distal condyle has its superior 

 margin elevated above the shaft, and terminated proximally in 

 a point. The ulna is comparatively large, and the proximal 

 carpal has an oval air cavity on its radial side. The sacral 

 vertebrae have their centra short, and medially constricted. 



The principal measurements of the remains of this species are 

 as follows : 



Greatest diameter of ulna at distal end, 15' '"'"• 



Transverse diameter of proximal carpal, 17- 



Antero-posterior diameter of outer distal condyle of wing 



metacarpal, 12-8 



Longitudinal extent of condyle, 11-6 



Transverse diameter of shaft above condyle, 1 1 -5 



Length of medial sacral vertebra, - . . . . 9-0 



Transverse diameter of centrum, - 8-4 



The above specimens are all from the Upper Cretaceous of 

 Western Kansas. 



Yale CoUege, May 22, 1876. 



Among the remains of Cretaceous Birds in the Yale 

 Museum, are specimens which indicate two undescribed 

 species of special interest. Both were of gigantic size, and 

 clearly belong to the Hesperornithidce, although quite distinct 

 from Hespercn-nis regalis Marsh, the type of the group.* The 



um has five pits i 

 ribs, and essentially no posterior emarginations. The tarso- 

 metatarsal bones present a distinctive feature which may prove 

 of generic value. On the inner side of the upper half of each, 

 there is a large tuberosity, somewhat similar to the ossified 



1872, and vol. x, p. 403, 1875. 

 , No. 66.— June, 1876. 



