APRACTOCLEIDUS TERETIPES. 619 



except for a small part of its extreme poster o-lateral border. The posterior border 

 of the clavicle is deeply concave, and its outer angle bears a very rough facet which 

 fits a corresponding depression in the scapula, the edge of which is roughened 

 in a similar fashion posteriorly to this point. The outer border of the clavicle 

 follows closely the lines of the scapula, and bears a small protuberance, corresponding 

 to the tubercle on the scapula, with gentle concavities on each side. As the 

 anterior of the clavicle is approached the border is found to retreat further within 

 the border of the scapula till the tip is fully 1 cm. behind the tip of the scapula. 

 The median border is straight, and follows the downward curve of the scapula 

 closely, although the median hollow is not conspicuous owing to the thickness of the 

 clavicle here. The anterior end of the clavicle is much roughened at the point 

 where the margin joins the median line. Except for the median border the whole 

 clavicle is of very thin bone. 



The coracoids {cor.) are fused into one massive bone, no trace of symphysis or 

 suture remaining. The combined bone might be described as built on a framework 

 of four thick bars — one stretching between the glenoids ; another, which thins near 

 its middle point, occupying the median line ; and one each side stretching from the 

 glenoid to the postero-lateral process (p.e.p.) ; while the intervening spaces are 

 occupied by bone, thin in proportion to its distance from any of those massive bars. 

 Thus at a point midway between the postero-lateral process and the centre of the 

 bone the thickness is less than 2 mm. The keel-like anterior prolongation of the 

 coracoids has already been described in reference to the scapula, and the glenoid and 

 surface of union with the scapula are very similar to the corresponding surfaces in 

 that bone, but make an angle of 135 degrees with each other. Between the glenoids 

 the bone is very massive and almost flat on its inner (visceral) side. Behind this flat 

 portion is a saucer-shaped depression, in the middle of which the bone is very thin 

 and pierced by a foramen (for.) which is situated practically in the middle of the 

 combined bone but slightly to the right of the median line. Continuing backwards 

 from this point along the median line the bone thickens again, and is 1'5 cm. thick 

 at a point only 4 cm. from the margin. The postero-external processes (p.e.p.) are 

 chiefly remarkable for their wide spread, the distance between them being slightly 

 greater than the length of the whole shoulder-girdle. The tips are rough and 

 deeply concave, indicating a cartilaginous termination. This condition is continued 

 along the posterior border of the left process for a distance of 9 cm., while the right 

 presents a smooth, rounded, finished edge at this part. Other two prominences, 

 each situated about mid-way between the postero-external angle and the median line, 

 terminate with thickened concave borders ; otherwise the posterior border of the 

 coracoids terminates with a fine edge of bone only about 1 mm. thick. The lateral 

 borders, from the glenoid to the postero-external angles, are concave, the bone being 

 thick and smooth until 14 cm. off the postero-external processes, when for 5 cm. the 

 edge of the bone is raised into a sharp ridge with rough tubercles, 



