150 PRACTICAL ZOOLOGY. 



noid muscle; cut away at its origin close fa r/ie 

 cricoid and demonstrate its action on the aryte- 

 noid cartilage and vocal cord. 



c. A broad muscle arising along the whole length of 

 the angle of the cricoid, whose fibers converge to 

 the arytenoid cartilage. This is the thyro-aryte- 

 noid muscle; cut it across near its origin, dis- 

 sect it loose, and by pulling it toward its origin 

 prove its action. 



d. On the posterior surfaces of the arytenoids is the 

 small arytenoid muscle. 



13. Cut between the arytenoid cartilages and remove one 

 of them. Examine the joint between the arytenoid 

 and cricoid. Note the synovia lubricating the joint. 



Trim away the muscle from the arytenoid cartilage 

 and study the shape more fully. Fit it again to its 

 place and recall the motions given by each muscle. 



14. Now examine the arytenoid cartilage and the vocal 

 cord of the opposite side ; move the arytenoid back 

 and forth, watching the vocal cord. 



15. Remove the epiglottis and cut into it to see its 

 structure. 



16. Dissect away the parts of the other side from the 

 inside, reviewing the above points. 



THE STARFISH. 



For this work there is needed : 



1. A set of dried specimens, one for each student ; such 

 a set may be used with successive classes and will last 

 for years if carefully handled and kept in a dry place. 



