114 MEMOIRS OF THE CARNEGIE MUSEUM 
“ Humerus about one third the length of the limb, with a stout twisted shaft that is 
greatly compressed near the distal end. Planes passed through the articulate ends 
of the humerus stand at an angle of 50°. The head is slightly rounded and is 
almost identical with Ichthyosawrus. ‘There are three distal facets; but they are 
not of equal size. The facet for the ulna (see fig. 24, w) is the largest, the one for 
the radius (7) next in size and the one opposite the pisiform (p) is rudimentary, for 
that bone was held in cartilage and did not articulate with the humerus. The 
Fic. 23. Superior view of fore paddle of Baptanodon marshi, Knight. Reduced about 2} times. A, humerus; 
p, pisiform ; 7, radius; uw, ulna; IL (?) second digit, first one wanting. 
facets are elliptical in form, and those opposite the ulna and radius elongated in the 
plane of articulation.” 
MEASUREMENTS OF HUMERI PERTAINING TO ENGLISH AND AMERICAN FORMS. 
| | | a 
| | Width | Width | 
| “greats | Proximal Distal | Remarks. 
pb | i) le 
100 mm.) 115 mm.| Type of species. 
No. 1955. Specimen in Yale Museum, B. discus.....| = 
| 
| 
WM, CRE ff ‘“ Univ. of Wyoming, B. marshi.| 190 1 eal 
No. 878. ft “* Carnegie Museum, B. discus... — 115mm.) — | Distal end wanting. 
| 130 | Type of the species. 
IN, 1%, IB, “« British Museum, 0. icenicus...| 145 | 124 
No. 47885.  “ us ve | 160 | 145 | 
Cotype O. icenicus in Leeds collection..... ........-++-+++| 164 115 _| 152 | Measurements given by Seeley. _ 
Posterior Limbs. — Professor Marsh in his original description of B. discus 
describes and figures a beautifully preserved hind (?) paddle (see fig. 25) of that 
