MUSCLES OF THE XE( .'K AND TRUNK 



107 



Costi-sternales. Four slips arising tendinously from the 

 sternal ribs, and inserted fleshy to the sternum. 



Costo-sternalis Extern us. This peculiar muscle, appa- 

 rently found only in Palamedeidse, replaces physiologically 

 the uncinate processes, as its broad ribbon-like belly runs 

 diagonally across the outer surface of the ribs. It arises by 

 a very thin flat tendon from the third, fourth, and fifth ribs, 

 and from the interspaces 

 between them. It is inserted 

 to the costal edge of the 

 sternum half an inch from the 

 posterior end. 



Caudal Muscles 



The caudal muscles (in 

 Palamedea) are illustrated in 

 the accompanying figure. 



Levator Coccygis. This 

 arises on each side from ilium, 

 from lateral faces of spinous 

 processes, and from trans- 

 verse processes of caudal 

 vertebrae. It is inserted on 

 to membrane covering rec- 

 trices. 



Ilio-coccygeus. On each 

 side there are two parts of 

 this muscle, bol;h entirely 

 fleshy. They arise from the FIG. 60. CAUDAL MUSCLES OF I'uiu- 

 ilium and the ilio-sacral liga- ntfdea (AFTEB BEDI)ABr> AND MlTCHELL )- 

 ment, and are inserted on to outer rectrix. 



Pubo-coccyyeiis Externus. This is the most posterior of 

 the muscles of the tail. It arises from the pubis and is 

 inserted on to external rectrix. 



Pubo-coccygeiis Interims. Arises in front of and below 

 the last-mentioned. The origin extends also on to the 

 ischium. The muscle is inserted on to last one or two caudal 

 vertebrae. 



