THE NECTURUS 15 



Appendicular Skeleton 

 Pectoral Girdle 



Remove one of the legs and work out the gitdle and the 

 leg or better, have prepared specimens in alcohol for study. 



The pectoral arch is mostly cartilage with the scapula the 

 only ossified element. The procoracoid extends anteriorly, 

 almost to the skull. The coracoid is the large posterior part 

 of the girdle in which the glenoid cavity is found. The line 

 between the coracoid and the procoracoid is not well 

 marked. The scapula is the ossified dorsal element, which 

 is capped by the suprascapula, a cartilaginous structure 

 along the dorsal border. The girdles of the two sides are 

 not articulated but overlap in the peculiar way, character- 

 istic of the amphibia. 



Pelvic Girdle 



The pelvic arch consists of an arrow shaped structure 

 composed of cartilage, but with some ossification in the 

 ischium and ilium. The ilium extends dorsally and is con- 

 nected with the sacral vertebra. This articulation varies 

 considerably as it has been found on at least four different 

 vertebrae, namely with the 18th, 19th, 20th and 21st. The 

 attachment sometimes varies on opposite sides of the verte- 

 bral column for example the ilium of one side may be 

 attached to the 18th vertebra while its fellow of the opposite 

 side articulates with the 19th. 



Anterior Limb 



This is best studied in cleared specimens, but can be 

 worked out from the formaldehyde material used in the 

 class. The anterior limb consists of humerus, radius, ulna, 

 carpals, metacarpals, and phalanges. It will be noted that 



