Dr. J. Murie on the Genus Colius. 267 



the breast-bone or sternum is long and remarkably shallow. 

 Indeed this want of depth is a striking feature, especially as 

 regards the pectoral plates : these are flattish and chevron- 

 shaped ; their united cross diameter is barely more than half 

 their length. In one specimen (PI. X. fig. 13) I found the outer 

 edges of the breast-plate possessed three denticulations, giving 

 a serrate appearance to each margin ; but in another, obtained 

 from the same locality, the borders were only slightly sinuous 

 and free from notching. 



On each side are two long delicate bony rods, the " xiphoid 

 processes," an " external " and an " internal,'' the tip of the 

 breast-plate being named the "middle'' one. The latter is a 

 trifle the shortest, the former two pairs terminally pedate. The 

 external xiphoid process runs on almost to the rib-facets ; the 

 internal process is shorter. The keel shallows gradually back- 

 wards with a very gentle curvature. Its anterior upright margin 

 is larger, below moderately produced, and above running into 

 the prominent sharp rostrum. This latter is indented, but barely 

 cleft, at the tip, and has a small fossa internally at its base, which 

 connects the shallow grooves lodging the coracoids. The elongate 

 triangular costal process, partially overlapped by the coracoid, 

 has four facets for as many ribs. 



The furcula (clavicle) at the sternal end possesses an inter- 

 mediate inflected process, the interclavicle or " hypocleidium." 

 The lower half of each furcular limb is flattened from above 

 downwards -, the upper half, on the contrary, is laterally com- 

 pressed, and widens out at its scapular junction into what goes 

 by the name of " prsecoracoid." 



The bladebone (scapula) is narrow, thin, and ensiform, with 

 a very slight terminal curvature. 



The shaft of the coracoid is on the whole rounded. Its 

 sternal end, the " epicoracoid " of writers, may be compared to 

 the blade of an oar. Superiorly the bone is united to the sca- 

 pula with moderate enlargement ; and there is a short depending 

 process of bone, the " mesocoracoid " of Parker, Each coracoid 

 is a trifle shorter than the sternal plate. 



There are eight ribs on either side of the thorax. The first 

 and second are short, and do not reach the sternum. The third 



