326 PROFESSOR OWEN ON THE SKELETON 



is a small coronoid process external and anterior to the outer articular surface. The 

 surangular part of the ramus shows an oval vacuity, about 3 lines by 2 lines ; the groove 

 defining the surangular from the angular part widens as it advances, and leads to an 

 oblong fissure between the surangular and dentary elements. 



The splenial element retains its distinctness posteriorly, and a groove upon the lower 

 margin of the ramus indicates the extent of its forward production : the posterior limits 

 of the posteriorly bifurcate dentary element are clearly defined. The right and left of 

 these elements coalesce to form a compressed, pointed symphysis, 1 inch long, half an 

 inch deep at the back part, gradually contracting forwards to a point, with a grooved 

 upper surface ; the upper margin of the symphysis is slightly convex lengthwise, the 

 under margin slightly concave lengthwise. 



The outer surface of the symphysial part of the jaw is roughened by numerous small 

 perforations and grooves, indicating the vascularity of the periosteum in connexion with 

 the reproductive matrix of the horny sheath of the beak : the tip of the premaxillary 

 has a similarly sculptured surface. 



The basihyal, including the urohyal, is 10 lines in length ; the fore end of the basihyal 

 is slightly expanded, and occupied by a trochlear articular surface, convex transversely, 

 concave A'ertically. The bone again expands to form the pair of concave oval articular 

 facets for the thyrohyals, beyond which it is continued as a slender pointed style 

 (urohyal) for about 4 lines ; the part anterior to this is the true basihyal. The thyro- 

 hyals (hyobranchyals) are slender, slightly bent styles, 2 inches long, swelling into a 

 small knob at both ends, the one articulated to the basihyal being rather the largest. 



§ 3. Scapular Arch and Appendage. 



The bladebone (PI. LI. fig. 1, si), 3 inches 8 lines in length, extends backward to the 

 ninth rib, gradually expanding vertically and more quickly flattening laterally to its free 

 extremity, which is truncate obliquely from above downward and backward. The 

 proximal end has opposite dimensions, being much expanded laterally or transversely 

 to the axis of the trunk, and narrowest vertically ; it presents a broad transverse 

 condyle, which is a little expanded at each end, to the coracoid. The outer end is the 

 broadest ; the inner one the most produced. The shaft of the scapula quickly con- 

 tracts to a transverse diameter of 3 lines, and then begins to grow thin and broad, 

 but as if with a kind of twist, the inner or medial border near the head of the bone 

 becoming the upper border about a fifth of the way from that end. The inner end of 

 the condyle is connected by a strong ligament with the end of the furculum. 



The coracoid (ib. 52) has a breadth at its sternal end of 14 lines : the medial side of 

 this end is thick, with the posterior angle produced ; the outer side is thin, and sends 

 off above the sternal articulation a lamelliform process. The inner side of the sternal 

 expansion is slightlv concave. The coracoid contracts to a diameter of 5 lines, con- 

 tinuing thick and convex along its medial border ; it sends off from the inner and back 



