triangular bone located posterior to the ceratohyal to which 

 it is bound by fine dentate processeso This bone supports 

 the remaining three branchiostegal rayso The interhyal is 

 a small triangular bone which joins the hyoid arch to the 

 hyomandibular and the symplectic by means of cartilageo The 

 urohyal is a flattened elongated bone which increases in width 

 posterior lyo Its anterior end is joined to the hypohyal^ 

 while its posterior end is free but has a surface for the 

 attachment of the muscles of the isthmus or the throato There 

 are seven branchial barSj, flattened^, slender^ curved bones 

 which become broaderj, longer^ and more curved posteriorlyo 



Of the various bones that make up the branchial arches j, 

 the basibranchials are made up of three bones joined together 

 in a straight line„ The first bone is joined to the ceratohyal, 

 the second is short with an oblique groove on each side^ 

 supporting the first gill archo The third bone is the longest 

 and near its anterior end there is an oblique groove like that 

 of the second bone. It supports the second gill arch„ The 

 hypobranchial is a short bone attached to the sides of the 

 second and third basibranchials„ The ceratobranchials are 

 extremely long^, roughly equal in lengthy and have a groove on 

 their lower surfacoo The epibranchials are short and much 

 curvedo The upper and lower pharyngeals are generally narrow 

 boneso 



The pectoral girdle or shoulder girdle is made up of a 

 group of so-called membrane boneso Its upper part is attached 

 to the skulli it cuts off the anterior part of the abdominal 

 cavity and at the same time supports the pelvic finso Among 

 these bonesp the posttemporal is a well -developed bifurcate 

 boneo Its dorsal limb is flat and is supported on the epiotic,, 

 while its ventral branch articulates with the central node of 

 the opisthotiCo The supraclavicle is a small oval bone with 

 its anterior end more or less pointedo Its lower edge is 

 thickenedo The anterior part of this bone joins the posterior 

 projection of the posttemporal and the main part of it rests 

 on the broad portion of the clavicle., The clavicle is a large 

 curved boneo Its dorsal end is broad and its ventral end is 

 thin and pointedo The main body of the bone is made up of 

 two wing-shaped parts j, an inner and an outer^ which meet at 

 roughly a right angleo The lower part of the outer wing-shaped 

 process is not very greatly developed,, The hypercoracoid is 

 a small flat bone^ the upper inner surface of which articulates 

 with the clavicles and there is a round hole in the center of 

 ito The hjrpocoracoid is located below and in contact with the 

 hypercoracoid and the anterior angle of its dorsal portion 

 joins the clavicleo The inferior projection is broad and 

 uniformly thine. The postclavicle is made up of two bonesp 

 the anterior and superior of which is lamellar and rather 

 kidney -shape do The posterio-inf erior one is broad anteriorly 



