EXTERNAL FEATURES OF NECTURUS 



Study the living animal, where it is possible to have a 

 specimen in the laboratory. If material is available, it is 

 very valuable to compare this Urodele with the representa- 

 tives of the other classes of vertebrates. 



Drawing 1. Make a drawing of a dorsal view showing the posi- 

 tion of the limbs and their relation to the body. What is the general 

 shape and plan of the body? 



Locate all of the openings of the body and list their 

 position. Is there a neck? What is the general shape of 

 the head? What is the shape and position of the mouth? 

 Are lips present? Note the position, shape and size of 

 the nose. Probe with a bristle and find the connection 

 with the mouth. What is the position, size and covering of 

 the eye? Is there an external auditory meatus. What 

 forms the gular fold? Why does this exist? Study the 

 gills and find the number, position, and character. Ex- 

 plore the openings into pharynx. What are the transverse 

 lines extending from the mid-dorsal to the mid-ventral line ? 

 How many of these are there between the anterior and 

 posterior limbs. Is the tail typical of a terrestrial or an 

 aquatic animal? What is the number of the appendages? 

 Are they of the tetrapod type? What is their position? 

 Compare them with the fins of the shark. Are the feet 

 webbed? How many toes are there on the limbs? Is the 

 type of leg that of the swimming animal? What is the 

 distribution of the color ? Is it the usual color distribution 

 found in water animals ? 



