8 



with the two lateral faces of unequal length, the superior being 

 the longer. The vertical perforating foramina join at the neural 

 canal, and there is a short subquadrate plane on each side of the 

 latter. There are no indications of chevron facets. These verte- 

 brse are different from any of those yet known in Polycotylus. 



Measurements. m. 



, anteroposterior . . .016 



Diameter of a cervical centrum ' vertical .... .026 



(transverse . . . .029 



/ antero-posterior 030 



Diameter of a dorsal ■? vertical 055 



(transverse . . ■ 056 



/antero-posterior . . .022 



Diameter of a proximal caudal ■? vertical 040 



(.transverse 062 



! antero-posterior . . . .015 

 vertical 017 

 transverse 038 



Diameter of neural canal of the proximal caudal above mea- 

 sured 012 



Do. of diapophysis of do. at base . . , . . .018 



The distal end of a proximal limb bone is much like the corre- 

 sponding part of Polycotylus latipinnis. It is relatively of large 

 size, flat, and strongly convex at the extremity, which is not 

 transversely truncate. A portion of another limb bone, perhaps 

 belonging to the distal segment, is symmetrical. The shaft is 

 broken off, and displays a large medullary cavity, with thin walls, 

 which soon terminates towards the articular end, in a fundus with 

 a fissure in the bottom. The proximal portion of a rib has a 

 truncate head of an oval outline. The inferior border presents a 

 low tuberosity, which may represent the capitulum. 



Measurements. m. 



Width of distal end of proximal limb bone . . . .109 



Thickness of the same '. .032 



_. , (longer 030 



Diameter of proximal end of a rib -j s i lorter qoq 



The bones above described were found together by the writer, 

 on a slope of the cream-colored soft sandstone, which lies above 

 the black shales of Cretaceous No. 4, near Amell's Creek, Mon- 

 tana. I suppose the formation to be the No. 5, or Fox Hills 

 group of Meek and Haj^den. Near them were found shark's teeth 



