BY DR. R. W. SHUFELDT, CM Z.S. 105 



(2639) this is broad and elliptical, with the major axis hori- 

 zontal, while in the other specimen it is almost circular. 

 More than this, in the first specimen mentioned there is a 

 well-marked "supraoccipital foramen'' present, which is 

 pierced by an elliptical foramen, placed vertically, that opens 

 mesially below by an extremely narrow strait into the super- 

 ior arc of the foramen magnum. At either side of the 

 cranium the glenoid fossa is very pronounced and markedly 

 concave transversely. 



As Owen has pointed out, "the vomer forms a bony, ver- 

 "tical septum, dividing the nasal cavity from the prespherioid 

 ^'forward." 



Whoever prepared these Army Medical Museum speci- 

 mens failed to preserve the hyoidean apparatus in either of 

 them, so no description of it can be furnished here. Sir 

 Richard Owen does not appear to have described this for 

 either the Echidna or the Duckbill; while Sir William H. 

 Flower, in his "Manual," gives a very excellent cut of the 

 lower surface of the hyoid of the Echidna (E. aculeata), and 

 briefly describes it in the text (pp. 242, 243). At this writing 

 I have not at hand a figure and description of the hyoid in 

 Ornith o rhy i ich u s . 



Figures 4, 7, and 8 of the accompanying plates present 

 the three principal viev/s of the mandible of the Duckbill; 

 and these, taken in connection with the admirable description 

 by Ov/en of this remarkable bone (p. 321), leave practically 

 nothing to be desired on this point. 



The Shoulder- girdle and Sternum: — Both Owen and 

 Flower, in their above-cited work, give quite full accounts 

 of the shouldei^- girdle and sternum in an Echidna and the 

 Duckbill; these accounts are illustrated for the last-named 

 animals, the differences being given in the text. Upon care- 

 fully comparing these two descriptions with the correspond- 

 ing bones of the skeletons at hand, I find that they practi- 

 cally agree in all essential particulars. These parts, in fact, 

 have long been known to comparative anatomists — that is, 

 since Flower published on the subject, for Owen's description 

 is very meagre and unsatisfactory. 



Attention is invited to the different way in which the 

 scapulse have been mounted in the two skeletons of the Duck- 

 bill. The bones are far apart in No. 1304, while in No. 2639 

 the upper thirds of these bones have not only been brought, 

 upon either side, flat against the cervical ribs, but actually 

 wired in that position. It would appear from the articula- 

 tions that neither of these is quite correct, ^nd doubtless it is 



