OSTEOLOGY OF HEMIBRANCHIATE FISHES— STARKS. 



627 



The hypocoracoid is attached broadly to the clavicle above, arches 

 away from it, and returns to its lower end, inclosing a triangular space. 

 Its lower ganoid part, the '' interclavicle," is rough on the outer sur- 

 face, but not otherwise differentiated from the rest of the bone. 



Fig. 1.— Right sihoulder girdle of Gasterosteus cataphractus from inner side and hypo- 

 coracoid OF LEFT shoulder GIRDLE FROM OUTER SIDE, tt, ACTINOSTS; .rf, CLAVICLE; ItlJOC, HYPO- 

 CORACOID; fiyiic, hy'percoracoid; p. pectoral fin; p<, posttemporal, and sd, superclavicle. 



The hypercoracoid is assisted for a short space anteriorly I)}' the 

 clavicle in inclosing the large hypercoracoid foramen. 



The actinosts are very small, about as wide as long, and have no 

 openings between them. The lowermost one is attached to the hypo- 

 coracoid, the remaining three to the hypercoracoid. 



