22 R. W. SJmfeldt 



one does, belongs, even should the fibular ridge be absent. In this 

 instance, if the specimen be held so that its posterior aspect is towards 

 one, then the outer tubercle for the attachment of the ligament span- 

 ning the tendinal groove below is the lower of the two tubercles 

 there found, while the inner one is considerably further up the shaft. 

 So then, when the ligament is there (as in life), it is directed obliquely 

 downwards from within to the outer side, being attached, of course, 

 at both extremities. The osseous bridge, also, spanning this tendinal 

 groove, has a similar obliquity in the same direction, but it is, as a rule, 

 never so well marked. That is the case here. So far as I am aware, 

 this rule holds throughout Aves, and by its observance and applica- 

 tion, the right or left tibio-tarsus can at once be made out correctly, 

 if those characters are present and in clear view as they are in this 

 specimen. 



I went much further than Professor Marsh apparently did in 

 comparing this specimen with the tibio-tarsi of existing birds; for I 

 not only compared it, with the utmost care, with the corresponding 

 bone in Cygnus, Larus and Branta, but added to the list Meleagris, 

 Grus, Ardea, Phcenicopterns, Mycteria, Nyctea, Aquila, and not a few 

 others with their numerous allies and affines. 



As Professor Marsh seemed to suspect, this bone belonged to some 

 large, generalized bird, from which a number of existing genera might 

 be more or less closely related. In some particulars, it best agrees 

 with Meleagris, and especially with respect to the circularity of the 

 outer condyle. The inner condyle, however, is deeper in the Turkey 

 than it is in Laornis, while in the former the two condyles are nearer 

 together — that is, the valley between them is narrower in Meleagris. 

 In general character, however, they are not far apart. Upon com- 

 paring it wdth the right tibio-tarsus of a specimen (adult) of Grus 

 canadensis (No. 820, Coll. U. S. Nat. Mus.), a still greater number of 

 characters are in agreement, though the circularity of the external 

 condyle is not present in the Crane. On the outer side of the bone in 

 Laornis there is a small, circumscribed little pit, between two short, 

 sharp, longitudinal crests, just posterior to the tubercle where the 

 oblique, tendinal Hgament, attaches in life. This is present in Griis, 

 though in the specimen at hand it is smaller. 



In comparing the specimen with Grus canadensis, the principal 

 difference to be noticed is that the shaft in the latter, on its anterior 

 aspect, is flatter, and presents two pretty well marked grooves for 

 the tendons, the inner groove being quite conspicuous below. The 

 shaft, in consequence, is more cylindrical below, then, than it is in 



