williston: Kansas pterodactyls. 5 



sents them as they are spread out in one plane. The bone is ver}- 

 thin throughout, with a slight thickening at the ischial {a) attachment 

 only. Ikying contiguous with the anterior projection, is a slender 

 ventral rib (//). It is possible that the curvature of this bone may be 

 inward, rather than outward. 



This peculiar structure of the pubis (I belive it represents the 

 pubis, and not the prepubis) seems to be quite similar to that which 

 obtains in the genus Rliaiiipliorliyiicliits, and, perhaps also, in Pfero- 

 dactyhis sucviciis {Cycuorliaiiipliits Seeley), and very different from that 

 found in other species of Picrodactyliis. 



The principal measurements of the above described specimen are as 

 follows: 



Antero-posterior expansion 40 millim. 



Length of symphysis 14 



Expanse of the united bones, as flattened 90 



Width of ischial process 11 



NYCTODACTYLUS. 



The type species of this genus was described as follows by its 

 author (loc. cit. supra) : 



"One of the smallest American species yet found is represented in 

 the Yale Museum by several bones of the wing, a number of vertebrae 

 and the nearly complete pelvis. The wing-bones preserved are elong- 

 ated and very slender. The pelvis is unusually small, and there are 

 five vertebrae in the sacrum. The last of the series indicates that the 

 tail was short. The following are the principal measurements of this 

 specimen : 



Length of ulna 1S7 millim. 



Length of metacarpal of wing- finger 300 



Antero-posterior diameter of outer condyle at distal 



end 15 



Transverse diameter of shaft, above condyles 1.3 



Length of first phalanx of wing-finger 347 



Extent of five vertebrae of sacrum 57 



This species, which may be called ]^trraiuul()ii orati/is, was about 

 two-thirds the size of P. 7<r/(>x Marsh. It iirobal)!}' measured al)out 

 ten feet between the tips of the expanded wings." 



In the December number of the same volume of the American Jour- 

 nal of Science, he described the genus as follows : 



"A second genus of American Pterodactyls is represented in the 

 Yale museum by several well preserved specimens. This genus is 

 nearly related to Plcraiunloii, but niay be readil}' dislingnishcd from it 



