316 THE MYOLOGY OF THE RAVEN. 



found beneath the skeleton of the tail, and which 

 beyond the fifth caudal vertebra merges to a great 

 extent with the fellow of the opposite side, almost 

 giving it the appearance of an azygos muscle. 



It arises, by means of a strong tendinous at- 

 tachment, on either side, from the inferior surface 

 of the diapophysis of that last vertebra which 

 anchyloses with the pelvic sacrum. It also finds 

 origin from similar positions on the first four free 

 caudal vertebrae ; this part of the muscle seems to 

 merge with the one of the opposite side to form a 

 tendinous attachment to the prominent hypapophysis 

 of the fifth caudal vertebra. But notwithstanding 

 this, the same muscle seems to spring again from 

 the under side of the transverse processes of the 

 remaining caudal vertebrae, and here is where the 

 blending seems to take place, not only with the oppo- 

 site muscle, but as a continuation of the first part 

 described. Finally, this latter fleshy portion becomes 

 inserted into the lower sides of the pygostyle, and 

 by a tendon on its middle infero-spine, or aborted 

 hypapophysis. 



This pair of muscles evidently antagonize the leva- 

 tors found on the upper side of the caudal vertebrae 

 and sacrum. 



Sir Kichard Owen, in his description of the caudal 

 muscles as they were found by him to exist in the 

 Apteryx, bestowed names upon them quite different 

 from those that I propose for them here. In the 

 nomenclature of this anatomist we find such names 

 as the iscliio-coccygeus, the quadratus coccygis, the 

 pubo-coccygeus, and others. A careful study on my 

 part of the musculature of this part of the skeleton and 

 its rectricial appendage in the Raven, convinced me that 



