280 Part III. — Twentieth Annual Report 



front of the clavicle. The scapula lies on the projecting plate-like 

 expansion of the clavicle. Inferiorly it is connected with the coracoid by 

 cartilage. 



The articular facet which corresponds to a basal element is larger in the 

 saithe than in the cod and lythe. It is, moreover, in the former rounded 

 in its lower extremity, and is thus sharply defined, whereas in the cod its 

 outer edge simply turns inwards in a slight bend to meet the margin of 

 the bone. In the lythe it is more defined than in the cod. 



Coracoid (Co.). 

 Cod, Fig. 13, PI. XI. : Saithe, Fig. 6, PI. XI. : Lythe, Fig. 30, PI. IV. 



The coracoid is a somewhat triangular bone which is bound to the 

 clavicle by means of a ligament attached to the long gusset-shaped 

 anterior part of the coracoid. This ligament is part of the cartilage 

 which unites the scapula to the clavicle. Superiorly the coracoid is 

 bound to the scapula by ligament. The anterior ligament-bearing part 

 is in the lythe and saithe broader than in the cod. The lower extremity 

 of the bone is narrow, and lodges in its extremity a ligament for binding 

 it to the posterior edge of the clavicle. Between the anterior and inferior 

 processes there is a thin transparent bony plate. The edge of this plate is 

 much more incurved in the cod thnn in the saithe and lythe, and rather 

 more in the lythe than in the saithe. 



The four basalia are attached to the hind edges of the scapula and 

 coracoid. 



Post-temporal (pt. T.). 

 Cod, Fig. 11, PI. XI. : Saithe, Fig. 5, PI. XI. : Lythe, Fig. 23, PL IV. 



The post-temporal is a V-shaped bone, having its two arms of unequal 

 length. The longer ends in a broadened thin extremity which rests on 

 the paroccipital ; the shorter has a serrated thick end which articulates 

 with a serrated area on the opisthotic. The angle between the two arms is 

 in the saithe more acute than in the lythe. In the saithe and lythe the 

 shorter arm bears a greater proportion to the length of the longer than 

 in the cod. 



In the saithe the anterior corner at the base of the short arm projects 

 as a strong triangular process, which is united by a short lamina to the 

 interspace between the bases of the two arms. In the lythe and cod the 

 corner is usually small, and there is no connecting bone lamina. 



The shape of the base of the bone differs in the three species. In the 

 saithe there is a prominent hind expansion at the base of the bone. In 

 the cod and saithe the lower edge is rounded. 



The post-temporal articulates below with the supraclavicle. 



Supraclavicle (s. CI.), 

 Cod, Fig. 9, PI. XL : Saithe, Fig. 3, PI. XI: Lythe, Fig. 25, PI. IV. 



The supraclavicle of the saithe is shorter than those of the lythe and 

 cod. It has, moreover, a widely-expanded upper extremity. The 

 articular hollow on the lower portion of the bone is nearly lialf the length 

 of the bone in the saithe, whereas it is considerably less than the half in 

 the lythe. 



The supraclavicle articulates with the post-temporal above and with the 

 clavicle belo^. 



