Brooks — The Osteology and Arthrology of the Haddock, 189 



wedge-shaped interspinous pieces of condensed fibrous tissue, tlie 

 ends of which are • embraced bj the fin-rays; behind this the fin- 

 rays are in close juxtaposition to the hypural bones, a small quan- 

 tity of the same fibrous tissue lying between their bases. 



Each fin-ray is composed of two long, slender rods of bone, 

 tapering to a very fine point ; these are closely bound together, 

 but diverge at their bases to embrace the cartilaginous continua- 

 tion of the interspinous bone ; at this part they are enlarged, and 

 present several tubercles for the insertion of the elevator and de- 

 pressor muscles of the fin, and for the attachment of ligaments. 



The ligaments ' of the vertebral column are neither numerous 

 nor very distinct. 



Strips of fibro-cartilage bind the edges of the centra together, 

 and membranous interspinous ligaments exist ; in the region of the 

 fins these expand into a dense network of fibrous and elastic tissue, 

 which binds the interspinous bones to the tips of the neural (or 

 haemal) spines. The articulation between the interspinous bones 

 and fin-rays is surrounded by a sort of capsular ligament, which 

 is continuous with bundles of fibres which bind the distal ends of 

 the interspinous bones together. The ligamentum subflavum is 

 a strong band of elastic tissue, which occupies a space in the upper 

 part of the neural canal, separated by a slight constriction from 

 the lower part, or true neural canal. A ligament connects the 

 anterior and posterior zya'pophyses, and above this is a strength- 

 ened portion of the interspinous ligament ; these are best seen in 

 the anterior vertebrae. 



The Shoulder-girdle and Pectoral Fin.—ThQ shoulder-girdle 

 consists of two bones, developed from cartilage — the scapula and 

 coracoid — and several membrane bones — the clavicle (PL IX., 

 fig. 24), supra-clavicle, and post-clavicle ; to these may be added 

 the post-temporal (Pi. IX., fig. 25), as belonging more properly to 

 the shoulder than to the head. 



The clavicle, being the largest bone, and articulating with four 

 of the others, may be described first : it is a curved bone, the con- 

 cavity being forwards, and the long axis running .downwards and 

 forwards ; above it is compressed from side to side ; below it forms 

 an elongated cone, sharply pointed at the inferior extremity, and 

 consisting of dense, compact tissue, solid to the very centre ; the 

 inferior extremity touches its fellow of the opposite side, being 



