184 Annals of the Carne(;ie Museum. 



Upon this aspect, the manubrium is seen to project directly forward 

 as a straight process. Below it, the anterior carinal margin is sharp, 

 being concave forwards above, and straight below. The carinal angle 

 is rounded. Muscular lines are barely seen on the side of the keel, 

 the surface here, as it is on the sternal body above it, smooth and 

 polished, the bone becoming only slightly thicker anteriorly below the 

 coracoidal beds. 



The keel is bounded inferiorly by an elegantly curved margin, ex- 

 tending from the carinal angle to nearly the end of the sternum 

 (Fig. 8). We are now better enabled to see the haemapophysial 

 facets, with the deep concavities between each and its neighbor. As 

 in so many birds, these interarticular cavities are the favorite sites of 

 the pneumatic foramina, and they are seen to be numerous here, oc- 

 cupying the bottoms of the pits. For the rest of the border behind, 

 it is sharp and continuous with the upper border of the xiphoidal 

 process, of which I also give a side view. 



As a whole, the costal process is triangular, with its apex at the 

 summit of the bone. 



Seen directly from above the asymmetry of the two sides of the 

 anterior border again becomes apparent, due to the method of articu- . 

 lation of the coracoids. A rounded notch exists in the median line, 

 flanked by a long facet on the right of it, and one, only half the size, 

 on the left. The manubrium is now seen to be triangular, with its 

 surface flat and smooth. 



Well within the anterior boundary of the body of the sternum, 

 upon this superior aspect of the bone, we observe a single elliptical 

 foramen of some size, situate in the median line, as is its major axis. 

 This leads to cavities in the thickened part of the front of the carina, 

 already alluded to in a paragraph above. 



From anterior border to xiphoidal extremity, and from summit of 

 costal process to summit of costal process this sternum is one general, 

 and by no means shallow, concavity. There are no interruptions of 

 surface, and all these parts enter into the conformation of the basin. 



For the most part it is smooth, and it is only in front that the sur- 

 face seems to be roughened by some peculiar little granulations. Fig. 

 9 being a direct anterior view of the sternum of this Heron, the 

 decussation of the coracoidal grooves is now best seen. The right 

 one, (the left in the drawing) being the lower anteriorly, and running 

 out over the top of the manubrium, while the left one, being the 

 higher, crossing it in front. 



