454 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 53 



this, by the toes, is extended onto the smallest piece of the slab (2); 

 while on the remaining piece (3) there is the impression of the hinder 

 two-thirds of the pelvis, five (5) coccygeal vertebrae, and the upper 

 portion of the left femur. No other bones are anywhere visible. 



So far as these impressions seem to indicate they are of bones 

 that may easily have belonged to some passerine bird of medium 

 proportions. I have made comparisons with several skeletons of 

 Passeres belonging to the collections of the United States National 

 Museum; and, taking everything into consideration, in so far as the 

 common American representatives of that group are concerned, I 

 find it comes as near a bird of the size of the Purple Grackle {Quis- 

 calus purpureus) as any other. So little of this fossil, however, has 

 been thus far discovered that it should occasion no surprise to find 

 that these bones belonged to some other species of an entirely different 

 group, not passerine at all. 



The skeleton of the Purple Grackle with which I have compared 

 it is No. 16708, from an individual collected on April 29, 1883, by 

 Mr. L. M. McCormick. In slab 1 of the plates, a invites attention 

 to the impressions of the lower end of a tibiotarsus, bearing its normal 

 relations to the tarso-metatarsus (b) of the same limb. As a is 

 imperfect, nothing would be conveyed by giving its length; I has a 

 length of 3.1 cms., the corresponding bone in Quiscalus purpureus 

 having a length of 3.9 cms. It will be noted that c is but faintly 

 impressed upon the slab, and I take it to be the other tibiotarsus, 

 the distal extremity of which is missing. This bone in Quiscalus 

 has a length of 5.5 cms., and the imperfect part of the specimen on 

 the slab measures 4.6 cms, in length, d invites attention to the 

 impressions of the toes, in which the proximal joint of hallux measures 

 considerably less than in Quiscalus purpureus, the latter having a 

 length of 1.4 cms., and in the fossil but 9 mm. (approx.). 



Passing to the remaining portion of this slab (3) it is to be noted 

 that the impression of the femur, which occupies about its normal 

 position in the skeleton, is of exactly the same size as we find it to 

 be in the Grackle with which I am comparing it. It does not admit, 

 however, of obtaining its length, as only the impression of the upper 

 portion is to be found on the slab. The impressions of the Jive 

 coccygeal vertebrae are in all respects just what we would find were 

 they made by those of the Grackle. The pygostyle is off the slab. Such 

 parts as are shown on the slab of the impression of the pelvis (3) I 

 have measured and compared with the corresponding parts in the 

 Grackle's skeleton, and, in measurements at least, they are practically 

 in agreement. 



It is quite possible that the bones that made these impressions 

 were those of a passerine bird about the size of the Purple Grackle, 

 but they are of such a nature, with respect to perfectness, number, 



