No. 2.] SHUFELDT ON THE OSTEOLOGY OP LAMID^. 357 



dinal canal between the two bones. The head of the coraooid rears 

 well above the glenoid ca^'it,y, in order to afford the required surface 

 upon its mesial aspect for the broad clavicular extremity that rests 

 against it; upon its opposite side it offers the usual surface to assist in 

 completing the cavity for head of humerus. The shaft of the bone is 

 very slender and cylindrical for its major i)art, and the wing-like exten- 

 sion, so broad in many birds, is here but a meager osseous scale attached 

 to the side of the shaft, for its outer and lower half, becoming continuous 

 with the formal dilatation of the bone below; for the sternal articulation, 

 this is transversely concave and very narrow. 



The minute pneumatic perforations of the scapulae and coracoids oc- 

 cupy their usual sites back of the glenoid cavity, under the protection 

 of the tendinal canal, at the heads of the bones. The united clavicles, 

 or the furculum, inclines decidedly to the U-shaped variety (Figs. 94, 

 95) ; we have already alluded to the fact as how broad, yet compressed, 

 their scapular ends are found to be; from these heads the shaft-like 

 portions fall downward, with a gentle curve backward to meet and sup 

 port the mesial and usual clavicular lamina, in birds where it is found, 

 which here lies in that recess formed by the anterior and concave border 

 of the carina of the sternum (Fig. 100). 



Directing our attention again to the shoulder-joint we discover that 

 this Shrike is another example of those birds in which that little peg- 

 like ossicle, the os humero-scapulare is found, here attached by its usual 

 ligaments to the upper and back part of the articulation and fulfilling 

 its ordinary function. The humerus of Lanius bears the closest resem- 

 blance to that bone as found in many of the family Turdidw — particu- 

 larly does this apply to Mimus polyglottus, a bird the Shrike not un- 

 successfully apes in point of external coloration. 



The head, in most individuals, is well bent, anconal, and supports a 

 short radial and not lofty crest, with the usual ulnar tuberosity over- 

 hanging an ample pneumatic fossa. The shaft is quite straight and 

 nearly cylindrical, its distal and expanded extremity presenting quite a 

 unique appearance (Figs. 96 and 97). The internal aud external con- 

 dyles are distinct processes, the former projecting almost directly back- 

 wards, the latter forwards and upwards ; the olecranon fossa is likewise 

 clearly defined, and on the palmar aspect we observe the oblique and 

 ulnar facets unusually prominent. The humerus is the only bone of the 

 pectoral limb that has air admitted to its interior, the bones of the anti- 

 brachium and pinion lacking this rather rare X)rerogative. 



The ulna is more than four times the bulk of the raduis, being, as in 

 most vertebrates, the main support of the forearm ; there is scarcely any 

 perceptible curvature along its well-balanced and cylindrical shaft, which 

 presents a row of distinct little tubercles for the bases of the quills of the 

 secondaries. Its proximal end presents for examination a prominent 

 olecranon process, directed backwards, and the greater and lesser sig- 

 moid cavities on its anconal aspect; the distal extremity is rather under 



