COUES, MYOLOGY OF THE ORNITHORHYNCHUS . 127 



IX. On the Myology of the Ornithorhynchus, 

 BY ELLIOTT COUES. 



ALTHOUGH the Ornithorhynclius has been repeatedly dissected in 

 Europe, such is not the case in this country; where, moreover, no 

 treatise on its anatomy is generally accessible. We publish, there- 

 fore, notes of a recent dissection of the muscles, rather with the 

 design of partly supplying a want that many students must have felt, 

 than with the idea of advancing anything new or specially important; 

 although, we should add, some of the muscular homologies are dis- 

 cussed upon a hypothesis of antero-posterior symmetry not yet gen- 

 erally received. We are indebted to Prof. Agassiz for the use of a 

 specimen from the Museum of Comparative Zoology, Cambridge, 

 received through the kind attentions of Prof. Wilder; an adult male, 

 in good condition, except that the head was severely shattered by a 

 charge of small shot. 



We find it convenient to group the muscles in the following man- 

 ner, which probably, also, is not entirely unnatural : 

 I. CUTANEOUS MUSCLES. 



II. VERTEBRAL MUSCLES. 



a. Of the Head. 



b. Of the Neck. 



a'. Anterior vertebral. 



b'. Posterior vertebral and not upward prolongation of 

 dorsal muscles. 



c. Of the Back. 



d. Of the Tail. 



III. CERVICAL MUSCLES: superficial, not connected with vertebra 



or scapula. 



IV. THORACIC MUSCLES. (Intrinsic.) 

 V. ABDOMINAL MUSCLES. ( " ) 



VI. PEUIN^AL MUSCLES. ( " ) 



VII. MUSCLES CONNECTING THE SHOULDER-GIRDLE WITH THE BODY. 

 VIII. MUSCLES OF THE ANTERIOR EXTREMITY. 



a. Acting upon the humerus. 



a'. From the body ; " long." 



b'. From the scapular arch ; " short." 



b. Acting upon the forearm. 



a'. From the body ; " long." 



b'. From the scapular arch; "long." 



c'. From the humerus ; " short." 



COMMUNICATIONS ESSEX INSTITUTE, VOL. VI. 17 March, 1871. 



