B. L. Moodie — Fossil Frogs of North America. 533 



The specimens represent two or more individuals. At least 

 there are two different grades of sizes. All of the specimens 

 are from quarry 9 of the Como Bluff in Wyoming; and are 

 now preserved in the Yale University Museum. 



The humerus (No. 1862, Tale University Museum) of what 

 I suppose to be the typical specimen is represented by the 

 lower end only, this portion measuring 6 mm -in length, by 2 ,nm 

 in distal width, by slightly more than half a millimeter in shaft 

 diameter. The well-developed characters of the bone indicate 

 a bufonid nature for the species. The ulno-radial articular 

 surfaces are as distinctly marked as in all modern Salientia with 

 which I am acquainted. The ball is apparently capped with 

 calcified cartilage. Above the ball is a distinct pit for muscular 

 attachment, precisely as in modern frogs. The shaft is quite 

 slender and nearly circular (fig. 1, a). 



The ilium (No. 1568 Yale University Museum) is quite 

 peculiar and will possibly be sufficiently characteristic to 

 sustain the validity of Professor Marsh's genus, Eobatrachus. 

 The element is of the right side. It measures 10 mm in greatest 

 length, by 3 min in greatest width, by 2 mm in greatest thickness 

 on the articular surface. The element is a slender rod, like 

 the modern salientian ilium, with the anterior end greatly nar- 

 rowed and pointed ; the pointed portion occupying one and one- 

 half millimeters. The shaft of the ilium is flattened laterally. 

 It expands in width from a little less than one-half a millimeter 

 to slightly more than three millimeters. The articular surface 

 is marked by four pits which are the surfaces of the synchon- 

 drosteal union of the halves of the pelvis. The element is 

 greatly thickened posteriorly, with a slightly developed, 

 posterior dorsal crest (fig. 1, c). 



The femur (No. 1862 Yale University Museum) is quite dis- 

 tinctly amphibian of the salientian type. It is a slender rod of 

 bone from which the epiphyses have been lost, leaving in their 

 place pits occupying the ends of the bone ; indicating the 

 slight development of the endochondral ossification, as in all 

 Amphibia. The lower end of the femur is divided into two 

 surfaces by an imperfect partition, as in most modern frogs. 

 The upper end is peculiar in having a well-developed crest 

 which, in life, was undoubtedly capped by a large amount of 

 cartilage. In the fossil state it has been preserved as a spine. 

 The femur measures 12 mm in length, by 3 mm in distal width, by 

 l mm in diameter of shaft, by 2"5 mm in proximal width. 



The tibio-fibula (No. 1394 Yale University Museum) is 

 represented by a portion of the lower end including 8 mm of the 

 element. Its characters are so clearly those of the modern 

 Salientia that a description is hardly necessary. The lower end 

 is divided by grooves one on either side, indicating the previous 



