Siiukp:i.dt on the Ostcoloffv of Cinchis Mcx/'cauNs. 217 



ill size to tiiat of their respective owners, and we might, in exten- 

 sive series of each, by exceedingly careful measurements, detect 

 relative diflerences. These remarks cannot be applied to the 

 genus Harporhynchiis^ as the pelvis there lias a verv striking 

 form, best expressed by sa3ing that it is more angular than the 

 others cited, the processes are more pronounced and sharper. In 

 Chichis^ as in other forms noted, the bone is broad across, with 

 the distal extremities of the pubic bones and iscliia flaring well 

 outwards ; the ilio-neural canals open ; the sacral vertebra; verv 

 broad, with numerous foramina or openings ex-isting among them. 



What we have just said in regard to the pelvis applies with 

 equal force to the shoulder girdle and sternum ; indeed, this latter 

 bone is singularly alike among the various genera that I have re- 

 ferred to ; the shape it assumes is that described by Professor Owen 

 in his Anatomy of Vertebrates, as the "Cantorial sternum," it 

 being the jDattern allotted to the vast majority of the class Avcs. 

 In front we find the manubrium bifurcated, and supported 

 upon a stout and produced base, directed upwards and outwards. 

 The body behind is 1-notched, the lateral xiphoidal processes 

 thus formed having dilated ends. The keel is dee^), convex be- 

 low, sharp and concave in front, forming an acute carinal angle 

 at the point of meeting. The costal processes are very lofty, 

 broad and directed forwards, having the facets for the sternal ribs 

 placed along their posterior borders, which meet on either side the 

 xiphoidal borders at a very obtuse angle. The '"merry-thought" 

 of Cinclus is delicately formed, having expanded upper extremi- 

 ties and a median plate l)elow. 



Our subject has, in addition to the usual number of bones in 

 the pectoral limb, quite a sizable sesamoid, to be found at the 

 back of the elbow : this bonelet is likewise found in Orcoscoptes 

 and may be a common character of other birds we have men- 

 tioned. The arm seems to be completely non-pneumatic, indeed 

 I have failed to find the apertures for the entrance of air in any 

 of the bones composing it. Several months ago my attention 

 was directed to a note. I think in the Proceedings of the Zoologi- 

 cal Society of London, in which some English observer says the 

 same of the European Dipper. This non-pneumatic condition 

 of the long bones, not only of the upper but also of the lower ex- 

 tremities, seems to hold good among all the other forms and 

 eenera we have thus far referred to in this article. 



