FEOG 207 



the boundary line between head and body ? 

 How much of the axial portion of the body 

 does the head form? Where is the widest 

 part of the head ? What is the shape of its 

 anterior end ? Where is the mouth ? What is 

 its shape ? In which direction does it open ? 

 How far around on the sides of the head does 

 the mouth extend ? Compare in position, shape, 

 size, mode of opening, etc., with the mouth of 

 the lobster. ISTote the eyes. — What is their 

 position? Shape? Color? Are there eye- 

 lids ? If so, how many ? How do they differ 

 in shape, size, color, texture, mobility, etc. ? 

 Compare with the lobster. How do you ac- 

 count for the position and prominence of the 

 eyes ? Can they in the live frog be depressed 

 and raised in the sockets ? If so, give reasons ? 

 Look for the bro^w-spot on a line connecting 

 the anterior borders of the eyes. Anterior to 

 the eyes find the external nares or nostrils. 

 Study their position, size, and shape. What 

 is the texture of the skin surrounding them ? 

 Can they be closed? What reasons can you 

 give for the position of the nostrils ? Posterior 

 to the eyes find the tympanic membranes. 

 What is their shape ? Size ? Color ? What is 

 the texture of the membrane ? How is it sup- 

 ported ? Is it tightly or loosely stretched ? 



How many paired openings does the head 

 bear ? How many unpaired ? What are they 

 in each case ? 

 The trunk. — What is its shape ? How does the 

 dorsal differ from the ventral surface in shape ? 

 Compress the trunk from side to side between 



